Deprecate chan_gtalk, chan_jingle, and res_jabber

chan_gtalk, chan_jingle, and res_jabber are now deprecated in favor of
using chan_motif and res_xmpp. They are a feature-equivalent
replacement and are written to be more easily maintainable.

(closes issue ASTERISK-20298)
Review: https://reviewboard.asterisk.org/r/2082/
Reported-by: Leif Madsen


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@372795 65c4cc65-6c06-0410-ace0-fbb531ad65f3