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/tests/preamble.rb

@@ -7,5 +7,17 @@ $:.unshift File.join(File.dirname(File.dirname(__FILE__)),'lib')
 $:.unshift File.dirname(__FILE__)
 
 def html5lib_test_files(subdirectory)
-    Dir[File.join(HTML5LIB_BASE, 'tests', subdirectory, '*.*')]
+  Dir[File.join(HTML5LIB_BASE, 'tests', subdirectory, '*.*')]
+end
+
+begin
+  require 'jsonx'
+rescue LoadError
+  class JSON
+    def self.parse json
+      json.gsub! /"\s*:/, '"=>'
+      json.gsub!(/\\u[0-9a-fA-F]{4}/) {|x| [x[2..-1].to_i(16)].pack('U')}
+      eval json
+    end
+  end
 end