1) FileTransferProxy will no longer return null for its disco items and cause a critical NPE. JM-655
2) Streamlined server disco items registration process so as to prevent confusion in the future. JM-656

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@3813 b35dd754-fafc-0310-a699-88a17e54d16e