Implement cdbxml schema version 3.3
Changes from 2.0.2
- Implement additions in cdbxml schema version 3.3
- Keywords are now represented as CultureFeed_Cdb_Data_Keyword objects, although
discouraged strings can be still used for backwards compatibility reasons - Add cdb scheme version parameter to CultureFeed_Cdb_Default constructor,
CultureFeed_Cdb_Item_Event::appendToDOM() etc. to allow different versions of
cdb xml to be produced - Deprecated CultureFeed_Cdb_Default::CDB_SCHEME_URL in favor of
CultureFeed_Cdb_Xml::namespaceUriForVersion() - Add new media type collaboration