adding two dialog container, one for dialogs which need destroy, another for rtptimeout checks.
both container will be checked on every loop of do_monitor instead of iterate through all dialogs.
(closes issue #17912)
Reported by: schmidts
Tested by: schmidts
Review: https://reviewboard.asterisk.org/r/917/
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@288063 65c4cc65-6c06-0410-ace0-fbb531ad65f3