add .hoerc containing excludes

so we can double-check the Manifest with `rake check_manifest`

.hoerc

@@ -0,0 +1,40 @@
+# -*- yaml -*-
+---
+# this regex is what `rake check_manifest` should consider excluded from the gem
+exclude: !ruby/regexp '/
+(^\.\/
+  ((\.git
+    |concourse
+    |gems
+    |ports
+    |suppressions
+    |tasks
+    |test
+    |tmp
+  )\/)
+  |\.(autotest
+     |codeclimate\.yml
+     |cross_rubies
+     |editorconfig
+     |gemtest
+     |github
+     |gitignore
+     |hoerc
+     |travis\.yml
+     )
+  |Gemfile.*
+  |Manifest.txt
+  |Rakefile
+  |appveyor\.yml
+  |build_all
+  |CHANGELOG.md
+  |CONTRIBUTING.md
+  |ROADMAP.md
+  |SECURITY.md
+  |STANDARD_RESPONSES.md
+  |Y_U_NO_GEMSPEC.md
+  |C_CODING_STYLE.*
+  |patches/sort-patches-by-date
+)
+|\.gitkeep
+/x'

Manifest.txt

@@ -63,8 +63,6 @@ ext/java/nokogiri/internals/XalanDTMManagerPatch.java
 ext/java/nokogiri/internals/XmlDeclHandler.java
 ext/java/nokogiri/internals/XmlDomParserContext.java
 ext/java/nokogiri/internals/XmlSaxParser.java
-ext/java/nokogiri/internals/dom2dtm/DOM2DTM.java
-ext/java/nokogiri/internals/dom2dtm/DOM2DTMdefaultNamespaceDeclarationNode.java
 ext/java/nokogiri/internals/c14n/AttrCompare.java
 ext/java/nokogiri/internals/c14n/C14nHelper.java
 ext/java/nokogiri/internals/c14n/CanonicalFilter.java
@@ -92,6 +90,8 @@ ext/java/nokogiri/internals/c14n/NameSpaceSymbTable.java
 ext/java/nokogiri/internals/c14n/NodeFilter.java
 ext/java/nokogiri/internals/c14n/UtfHelpper.java
 ext/java/nokogiri/internals/c14n/XMLUtils.java
+ext/java/nokogiri/internals/dom2dtm/DOM2DTM.java
+ext/java/nokogiri/internals/dom2dtm/DOM2DTMdefaultNamespaceDeclarationNode.java
 ext/nokogiri/depend
 ext/nokogiri/extconf.rb
 ext/nokogiri/html_document.c
@@ -236,6 +236,3 @@ lib/xsd/xmlparser/nokogiri.rb
 patches/libxml2/0001-Revert-Do-not-URI-escape-in-server-side-includes.patch
 patches/libxml2/0002-Fix-nullptr-deref-with-XPath-logic-ops.patch
 patches/libxml2/0003-Fix-infinite-loop-in-LZMA-decompression.patch
-patches/sort-patches-by-date
-suppressions/README.txt
-suppressions/nokogiri_ruby-2.supp