res_pjsip_registrar_expire.c: Made use ao2 container template routines and...

res_pjsip_registrar_expire.c: Made use ao2 container template routines and eliminated some RAII_VAR() usage.

* Converted the contact_autoexpire container to use the ao2 template hash
and cmp functions.  Also made use the OBJ_SEARCH_xxx names instead of the
deprecated names.

* Eliminates several unnecessary uses of RAII_VAR().

Review: https://reviewboard.asterisk.org/r/4524/


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@433622 65c4cc65-6c06-0410-ace0-fbb531ad65f3