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/treewalkers/simpletree.rb

@@ -0,0 +1,48 @@
+require 'html5/treewalkers/base'
+
+module HTML5
+  module TreeWalkers
+    module SimpleTree
+      class TreeWalker < HTML5::TreeWalkers::Base
+        include HTML5::TreeBuilders::SimpleTree
+
+        def walk(node)
+          case node
+          when Document, DocumentFragment
+            return
+
+          when DocumentType
+            yield doctype(node.name, node.public_id, node.system_id)
+
+          when TextNode
+            text(node.value) {|token| yield token}
+
+          when Element
+            if VOID_ELEMENTS.include?(node.name)
+              yield empty_tag(node.name, node.attributes, node.hasContent())
+            else
+              yield start_tag(node.name, node.attributes)
+              for child in node.childNodes
+                walk(child) {|token| yield token}
+              end
+              yield end_tag(node.name)
+            end
+
+          when CommentNode
+            yield comment(node.value)
+
+          else
+            puts '?'
+            yield unknown(node.class)
+          end
+        end
+
+        def each
+          for child in @tree.childNodes
+            walk(child) {|node| yield node}
+          end
+        end
+      end
+    end
+  end
+end