servo: Merge #7117 - Reenable "Use one Python virtual environment for…

… all mach commands" (from frewsxcv:python-venv); r=jdm

Address the issues brought up by servo/servo#7103

The revert requires an upgrade to wptrunner (for the mozlog 3.0 compatibility) because the latest wptrunner depends on [this](w3c/wpt-tools#27))

/cc Ms2ger metajack

Source-Repo: https://github.com/servo/servo
Source-Revision: 4e6bbe227299b3b8a08cba7e613952806ada4402

UltraBlame original commit: 3b54edfbc4495f65e8bc23a047821d2a3bf2d753

servo/.gitignore

@@ -36,9 +36,7 @@ android
 /
 obj
 /
-tests
-/
-wpt
+python
 /
 _virtualenv
 *

servo/python/README.md

@@ -28,139 +28,6 @@ test
 harnesses
 .
 =
-mozdebug
-=
-mozbase
-module
-containing
-information
-about
-various
-debuggers
-.
-This
-can
-be
-updated
-by
-copying
-the
-latest
-version
-from
-https
-:
-/
-/
-hg
-.
-mozilla
-.
-org
-/
-mozilla
--
-central
-/
-file
-/
-tip
-/
-testing
-/
-mozbase
-/
-mozdebug
-=
-mozinfo
-=
-Mozbase
-module
-for
-extracting
-information
-about
-the
-host
-hardware
-/
-os
-.
-This
-can
-be
-updated
-by
-copying
-the
-latest
-version
-from
-hg
-.
-mozilla
-.
-org
-/
-mozilla
--
-central
-/
-file
-/
-tip
-/
-testing
-/
-mozbase
-/
-mozinfo
-=
-mozlog
-=
-A
-mozbase
-logging
-module
-required
-for
-wptrunner
-output
-and
-command
-line
-arguments
-.
-This
-can
-be
-updated
-by
-copying
-the
-latest
-version
-from
-hg
-.
-mozilla
-.
-org
-/
-mozilla
--
-central
-/
-file
-/
-tip
-/
-testing
-/
-mozbase
-/
-mozlog
-=
 servo
 =
 servo
@@ -186,31 +53,3 @@ for
 this
 code
 .
-=
-=
-toml
-=
-=
-Python
-module
-for
-reading
-toml
-files
-.
-This
-can
-be
-updated
-from
-https
-:
-/
-/
-github
-.
-com
-/
-uiri
-/
-toml