[JM-1332] Light WebDAV servlet implemented that will be used for file sharing in MUC rooms.  Currently does Basic Auth.  Other auth's will be implemented as needed for SparkWeb and possible some extra.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@10242 b35dd754-fafc-0310-a699-88a17e54d16e