Update chan_iax2 to use linkedlists.h for users and peers. Modify the way...

Update chan_iax2 to use linkedlists.h for users and peers. Modify the way get_from_jb and expire_registry works to get rid of certain crash scenarios. Finally - change the way expire_registry works when realtime autoclear is enabled to be a bit more efficient.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@24422 65c4cc65-6c06-0410-ace0-fbb531ad65f3