Committing beginnings of remote roster plugin, for spectrum integration (and anything else that might use it).  This is completely non-functional atm.  Just doing work on UI and working out some logistics.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@12875 b35dd754-fafc-0310-a699-88a17e54d16e