Continue to move variables into the sip_cfg structure to make them easier to handle in the future as a group of settings for a group of devices. 
At some point, I want one sip_cfg per domain handled, so we can have "group" settings.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@171400 65c4cc65-6c06-0410-ace0-fbb531ad65f3