Ruby 1.9 Compatibility

Completely removed the html5lib sanitizer.
Fixed the string-handling to work in both
Ruby 1.8.x and 1.9.2. There are still,
inexplicably, two functional tests that
fail. But the rest seems to work quite well.

attic/vendor/plugins/HTML5lib/lib/html5/treebuilders.rb

@@ -0,0 +1,24 @@
+module HTML5
+  module TreeBuilders
+
+    class << self
+      def [](name)
+        case name.to_s.downcase
+        when 'simpletree' then
+          require 'html5/treebuilders/simpletree'
+          SimpleTree::TreeBuilder
+        when 'rexml' then
+          require 'html5/treebuilders/rexml'
+          REXML::TreeBuilder
+        when 'hpricot' then
+          require 'html5/treebuilders/hpricot'
+          Hpricot::TreeBuilder
+        else
+          raise "Unknown TreeBuilder #{name}"
+        end
+      end
+
+      alias :get_tree_builder :[]
+    end
+  end
+end