Deprecate Document(Save|Update|Delete)Event and add new Document(Created|Updated|Deleted)Event in xwiki-bridge instead

This to comply to the naming strategy we've agreed upon here http://xwiki.markmail.org/thread/62a3yaxiuosx4f6o

We are also moving them to xwiki-bridge module to emphasis the fact they are not meant to stay since they have an implicit dependency over XWikiDocument and XWikiContext (as source and data being passed).