Add a c() option for the Jack() application and JACK_HOOK() funciton for supplying

a custom client name.  Using the channel name is still the default.  This was done
at the request of Jared Smith.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@114533 65c4cc65-6c06-0410-ace0-fbb531ad65f3