Adding new config option "limitpeersonly" to only apply call limits

to the peer side of a type=friend. 

This is for trying to support BJ in his quest to solve some issues
with the queue system and type=friend objects.

BJ: Please test!


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@47201 65c4cc65-6c06-0410-ace0-fbb531ad65f3