bridge_native_rtp: Fix native bridge tech being incompatible when it should be.

When checking compatability for the native RTP bridge technology there is a
race condition between clearing framehooks that are destroyed when leaving
certain bridges with certain technologies (such as bridge_native_rtp) and
joining bridges with the bridge_native_rtp technology. Yes, that means a
channel in a native RTP bridge could move to another native RTP bridge and
be considered incompatible with the new native RTP bridge causing it to
revert to a simple bridge technology0. This fixes that bug by ignoring
framehooks that have been marked for destruction when checking for
compatibility with the bridge_native_rtp technology.


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@391453 f38db490-d61c-443f-a65b-d21fe96a405b
Remove incorrect comment about local channel optimization occurring when performing an attended transfer on an entire bridge.



git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@391455 f38db490-d61c-443f-a65b-d21fe96a405b