Merge changes from team/group/sip-tcptls

This set of changes introduces TCP and TLS support for chan_sip.  There are various
new options in configs/sip.conf.sample that are used to enable these features.  Also,
there is a document, doc/siptls.txt that describes some things in more detail.

This code was implemented by Brett Bryant and James Golovich.  It was reviewed
by Joshua Colp and myself.  A number of other people participated in the testing
of this code, but since it was done outside of the bug tracker, I do not have their
names.  If you were one of them, thanks a lot for the help!

(closes issue #4903, but with completely different code that what exists there.)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@99085 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CREDITS

@@ -56,7 +56,7 @@ Anthony Minessale II - Countless big and small fixes, and relentless forward
 	and sip configs.
 	anthmct(AT)yahoo.com              http://www.asterlink.com
 
-James Golovich - Innumerable contributions
+James Golovich - Innumerable contributions, including SIP TCP and TLS support.
 	You can find him and asterisk-perl at http://asterisk.gnuinter.net
 
 Andre Bierwirth - Extension hints and status
@@ -176,6 +176,11 @@ Marta Carbone - console_video and the astobj2 framework
 Luigi Rizzo - astobj2, console_video, windows build, chan_oss cleanup,
 	and a bunch of infrastructure work (loader, new_cli, ...)
 
+Brett Bryant - digit option for musiconhold selection, ENUMQUERY and ENUMRESULT functions,
+	feature group configuration for features.conf, per-file CLI debug and verbose settings,
+	TCP and TLS support for SIP, and various bug fixes.
+	brettbryant(AT)gmail.com
+
 === OTHER CONTRIBUTIONS ===
 John Todd - Monkey sounds and associated teletorture prompt
 Michael Jerris - bug marshaling