HTML5lib is Back.

Synced with latest version of HTML5lib, which fixes problem with Astral plane characters.
I should really do some tests, but the HTML5lib Sanitizer seems to be 2-5 times slower than the old sanitizer.

vendor/plugins/HTML5lib/lib/html5lib/html5parser/initial_phase.rb

@@ -0,0 +1,49 @@
+require 'html5lib/html5parser/phase'
+
+module HTML5lib
+  class InitialPhase < Phase
+
+    # This phase deals with error handling as well which is currently not
+    # covered in the specification. The error handling is typically known as
+    # "quirks mode". It is expected that a future version of HTML5 will define this.
+
+    def processEOF
+      @parser.parseError(_('Unexpected End of file. Expected DOCTYPE.'))
+      @parser.phase = @parser.phases[:rootElement]
+      @parser.phase.processEOF
+    end
+
+    def processComment(data)
+      @tree.insertComment(data, @tree.document)
+    end
+
+    def processDoctype(name, error)
+      @parser.parseError(_('Erroneous DOCTYPE.')) if error
+      @tree.insertDoctype(name)
+      @parser.phase = @parser.phases[:rootElement]
+    end
+
+    def processSpaceCharacters(data)
+      @tree.insertText(data, @tree.document)
+    end
+
+    def processCharacters(data)
+      @parser.parseError(_('Unexpected non-space characters. Expected DOCTYPE.'))
+      @parser.phase = @parser.phases[:rootElement]
+      @parser.phase.processCharacters(data)
+    end
+
+    def processStartTag(name, attributes)
+      @parser.parseError(_("Unexpected start tag (#{name}). Expected DOCTYPE."))
+      @parser.phase = @parser.phases[:rootElement]
+      @parser.phase.processStartTag(name, attributes)
+    end
+
+    def processEndTag(name)
+      @parser.parseError(_("Unexpected end tag (#{name}). Expected DOCTYPE."))
+      @parser.phase = @parser.phases[:rootElement]
+      @parser.phase.processEndTag(name)
+    end
+
+  end
+end