🏗 Merge C++ into python codebase (esphome#504)

## Description:

Move esphome-core codebase into esphome (and a bunch of other refactors). See esphome/feature-requests#97

Yes this is a shit ton of work and no there's no way to automate it :( But it will be worth it 👍

Progress:
- Core support (file copy etc): 80%
- Base Abstractions (light, switch): ~50%
- Integrations: ~10%
- Working? Yes, (but only with ported components).

Other refactors:
- Moves all codegen related stuff into a single class: `esphome.codegen` (imported as `cg`)
- Rework coroutine syntax
- Move from `component/platform.py` to `domain/component.py` structure as with HA
- Move all defaults out of C++ and into config validation.
- Remove `make_...` helpers from Application class. Reason: Merge conflicts with every single new integration.
- Pointer Variables are stored globally instead of locally in setup(). Reason: stack size limit.

Future work:
- Rework const.py - Move all `CONF_...` into a conf class (usage `conf.UPDATE_INTERVAL` vs `CONF_UPDATE_INTERVAL`). Reason: Less convoluted import block
- Enable loading from `custom_components` folder.

**Related issue (if applicable):** esphome/feature-requests#97

**Pull request in [esphome-docs](https://github.com/esphome/esphome-docs) with documentation (if applicable):** esphome/esphome-docs#<esphome-docs PR number goes here>

## Checklist:
  - [ ] The code change is tested and works locally.
  - [ ] Tests have been added to verify that the new code works (under `tests/` folder).

If user exposed functionality or configuration variables are added/changed:
  - [ ] Documentation added/updated in [esphomedocs](https://github.com/OttoWinter/esphomedocs).

.clang-format

@@ -0,0 +1,137 @@
+Language:        Cpp
+AccessModifierOffset: -1
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: DontAlign
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: MultiLine
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterClass:      false
+  AfterControlStatement: false
+  AfterEnum:       false
+  AfterFunction:   false
+  AfterNamespace:  false
+  AfterObjCDeclaration: false
+  AfterStruct:     false
+  AfterUnion:      false
+  AfterExternBlock: false
+  BeforeCatch:     false
+  BeforeElse:      false
+  IndentBraces:    false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Attach
+BreakBeforeInheritanceComma: false
+BreakInheritanceList: BeforeColon
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit:     120
+CommentPragmas:  '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: true
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks:   Preserve
+IncludeCategories:
+  - Regex:           '^<ext/.*\.h>'
+    Priority:        2
+  - Regex:           '^<.*\.h>'
+    Priority:        1
+  - Regex:           '^<.*'
+    Priority:        2
+  - Regex:           '.*'
+    Priority:        3
+IncludeIsMainRegex: '([-_](test|unittest))?$'
+IndentCaseLabels: true
+IndentPPDirectives: None
+IndentWidth:     2
+IndentWrappedFunctionNames: false
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 1
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 2000
+PointerAlignment: Right
+RawStringFormats:
+  - Language:        Cpp
+    Delimiters:
+      - cc
+      - CC
+      - cpp
+      - Cpp
+      - CPP
+      - 'c++'
+      - 'C++'
+    CanonicalDelimiter: ''
+    BasedOnStyle:    google
+  - Language:        TextProto
+    Delimiters:
+      - pb
+      - PB
+      - proto
+      - PROTO
+    EnclosingFunctions:
+      - EqualsProto
+      - EquivToProto
+      - PARSE_PARTIAL_TEXT_PROTO
+      - PARSE_TEST_PROTO
+      - PARSE_TEXT_PROTO
+      - ParseTextOrDie
+      - ParseTextProtoOrDie
+    CanonicalDelimiter: ''
+    BasedOnStyle:    google
+ReflowComments:  true
+SortIncludes:    false
+SortUsingDeclarations: false
+SpaceAfterCStyleCast: true
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles:  false
+SpacesInContainerLiterals: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Auto
+TabWidth:        2
+UseTab:          Never

.clang-tidy

@@ -0,0 +1,127 @@
+---
+Checks: >-
+  *,
+  -abseil-*,
+  -android-*,
+  -boost-*,
+  -bugprone-macro-parentheses,
+  -cert-dcl50-cpp,
+  -cert-err58-cpp,
+  -clang-analyzer-core.CallAndMessage,
+  -clang-analyzer-osx.*,
+  -clang-analyzer-security.*,
+  -cppcoreguidelines-avoid-goto,
+  -cppcoreguidelines-c-copy-assignment-signature,
+  -cppcoreguidelines-owning-memory,
+  -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
+  -cppcoreguidelines-pro-bounds-constant-array-index,
+  -cppcoreguidelines-pro-bounds-pointer-arithmetic,
+  -cppcoreguidelines-pro-type-const-cast,
+  -cppcoreguidelines-pro-type-cstyle-cast,
+  -cppcoreguidelines-pro-type-member-init,
+  -cppcoreguidelines-pro-type-reinterpret-cast,
+  -cppcoreguidelines-pro-type-static-cast-downcast,
+  -cppcoreguidelines-pro-type-union-access,
+  -cppcoreguidelines-pro-type-vararg,
+  -cppcoreguidelines-special-member-functions,
+  -fuchsia-*,
+  -fuchsia-default-arguments,
+  -fuchsia-multiple-inheritance,
+  -fuchsia-overloaded-operator,
+  -fuchsia-statically-constructed-objects,
+  -google-build-using-namespace,
+  -google-explicit-constructor,
+  -google-readability-braces-around-statements,
+  -google-readability-casting,
+  -google-readability-todo,
+  -google-runtime-int,
+  -google-runtime-references,
+  -hicpp-*,
+  -llvm-header-guard,
+  -llvm-include-order,
+  -misc-unconventional-assign-operator,
+  -misc-unused-parameters,
+  -modernize-deprecated-headers,
+  -modernize-pass-by-value,
+  -modernize-pass-by-value,
+  -modernize-return-braced-init-list,
+  -modernize-use-auto,
+  -modernize-use-default-member-init,
+  -modernize-use-equals-default,
+  -mpi-*,
+  -objc-*,
+  -performance-unnecessary-value-param,
+  -readability-braces-around-statements,
+  -readability-else-after-return,
+  -readability-implicit-bool-conversion,
+  -readability-named-parameter,
+  -readability-redundant-member-init,
+  -warnings-as-errors,
+  -zircon-*
+WarningsAsErrors: '*'
+HeaderFilterRegex: '^.*/src/esphome/.*'
+AnalyzeTemporaryDtors: false
+FormatStyle:     google
+CheckOptions:
+  - key:             google-readability-braces-around-statements.ShortStatementLines
+    value:           '1'
+  - key:             google-readability-function-size.StatementThreshold
+    value:           '800'
+  - key:             google-readability-namespace-comments.ShortNamespaceLines
+    value:           '10'
+  - key:             google-readability-namespace-comments.SpacesBeforeComments
+    value:           '2'
+  - key:             modernize-loop-convert.MaxCopySize
+    value:           '16'
+  - key:             modernize-loop-convert.MinConfidence
+    value:           reasonable
+  - key:             modernize-loop-convert.NamingStyle
+    value:           CamelCase
+  - key:             modernize-pass-by-value.IncludeStyle
+    value:           llvm
+  - key:             modernize-replace-auto-ptr.IncludeStyle
+    value:           llvm
+  - key:             modernize-use-nullptr.NullMacros
+    value:           'NULL'
+  - key:             readability-identifier-naming.LocalVariableCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ClassCase
+    value:           'CamelCase'
+  - key:             readability-identifier-naming.StructCase
+    value:           'CamelCase'
+  - key:             readability-identifier-naming.EnumCase
+    value:           'CamelCase'
+  - key:             readability-identifier-naming.EnumConstantCase
+    value:           'UPPER_CASE'
+  - key:             readability-identifier-naming.StaticConstantCase
+    value:           'UPPER_CASE'
+  - key:             readability-identifier-naming.StaticVariableCase
+    value:           'UPPER_CASE'
+  - key:             readability-identifier-naming.GlobalConstantCase
+    value:           'UPPER_CASE'
+  - key:             readability-identifier-naming.ParameterCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.PrivateMemberPrefix
+    value:           'NO_PRIVATE_MEMBERS_ALWAYS_USE_PROTECTED'
+  - key:             readability-identifier-naming.PrivateMethodPrefix
+    value:           'NO_PRIVATE_METHODS_ALWAYS_USE_PROTECTED'
+  - key:             readability-identifier-naming.ClassMemberCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ClassMemberCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ProtectedMemberCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ProtectedMemberSuffix
+    value:           '_'
+  - key:             readability-identifier-naming.FunctionCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ClassMethodCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ProtectedMethodCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.ProtectedMethodSuffix
+    value:           '_'
+  - key:             readability-identifier-naming.VirtualMethodCase
+    value:           'lower_case'
+  - key:             readability-identifier-naming.VirtualMethodSuffix
+    value:           ''

.gitignore

@@ -25,12 +25,6 @@ wheels/
 *.egg
 MANIFEST
 
-# PyInstaller
-#  Usually these files are written by a python script from a template
-#  before PyInstaller builds the exe, so as to inject date/other infos into it.
-*.manifest
-*.spec
-
 # Installer logs
 pip-log.txt
 pip-delete-this-directory.txt
@@ -51,36 +45,9 @@ coverage.xml
 *.mo
 *.pot
 
-# Django stuff:
-*.log
-local_settings.py
-db.sqlite3
-
-# Flask stuff:
-instance/
-.webassets-cache
-
-# Scrapy stuff:
-.scrapy
-
-# Sphinx documentation
-docs/_build/
-
-# PyBuilder
-target/
-
-# Jupyter Notebook
-.ipynb_checkpoints
-
 # pyenv
 .python-version
 
-# celery beat schedule file
-celerybeat-schedule
-
-# SageMath parsed files
-*.sage.py
-
 # Environments
 .env
 .venv
@@ -90,19 +57,46 @@ ENV/
 env.bak/
 venv.bak/
 
-# Spyder project settings
-.spyderproject
-.spyproject
-
-# Rope project settings
-.ropeproject
-
-# mkdocs documentation
-/site
-
 # mypy
 .mypy_cache/
 
+.pioenvs
+.piolibdeps
+.vscode
+CMakeListsPrivate.txt
+CMakeLists.txt
+
+# User-specific stuff:
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/dictionaries
+
+# Sensitive or high-churn files:
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.xml
+.idea/**/dataSources.local.xml
+.idea/**/dynamic.xml
+
+# CMake
+cmake-build-debug/
+cmake-build-release/
+
+CMakeCache.txt
+CMakeFiles
+CMakeScripts
+Testing
+Makefile
+cmake_install.cmake
+install_manifest.txt
+compile_commands.json
+CTestTestfile.cmake
+/*.cbp
+
+.clang_complete
+.gcc-flags.json
+
 config/
 tests/build/
 tests/.esphome/
+/.temp-clang-tidy.cpp