Add final part of previously committed work for answered elsewhere in queue - the...

Add final part of previously committed work for answered elsewhere in queue - the missing piece that started with app_dial() earlier on.

This is to avoid having the list and counter of missed calls being touched by queue calls. Add the C option to queue() and nothing
will be logged on phones that support the Reason: header on SIP cancel, like the SNOM phones.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@171924 65c4cc65-6c06-0410-ace0-fbb531ad65f3