Implement Bdo module. Also added some documentation and missing values, as well as support for attr_collection additions.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@713 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/HTMLModule.php

@@ -15,6 +15,7 @@ class HTMLPurifier_HTMLModule
     var $elements = array();
     var $info = array();
     var $content_sets = array();
+    var $attr_collection = array();
 }
 
 ?>