HTML5lib Sanitizer

Replaced native Sanitizer with HTML5lib version.
Synced with latest Maruku.

vendor/plugins/HTML5lib/lib/html5lib/treebuilders.rb

@@ -0,0 +1,21 @@
+module HTML5lib
+module TreeBuilders
+
+  def self.getTreeBuilder(name)
+    case name.to_s.downcase
+        when 'simpletree' then
+            require 'html5lib/treebuilders/simpletree'
+            SimpleTree::TreeBuilder
+        when 'rexml' then
+            require 'html5lib/treebuilders/rexml'
+            REXMLTree::TreeBuilder
+        when 'hpricot' then
+            require 'html5lib/treebuilders/hpricot'
+            Hpricot::TreeBuilder
+        else
+            raise "Unknown TreeBuilder #{name}"
+    end
+  end
+
+end
+end