Add a cleaned up drop-in replacement for res_jabber called res_xmpp. This provides the same externally facing functionality but is implemented differently internally.

This is currently not built by default but this will be changed once chan_jingle2 (insert actual name in your head when reading this after it has been merged)
is in the tree.

Review: https://reviewboard.asterisk.org/r/1983/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@369527 65c4cc65-6c06-0410-ace0-fbb531ad65f3