Re-work ref count handling of MoH classes using astobj2 to resolve crashes.

(closes issue #13566)
Reported by: igorcarneiro
Tested by: russell
Review: http://reviewboard.digium.com/r/106/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@166273 65c4cc65-6c06-0410-ace0-fbb531ad65f3