* Simplify native bridge code in ast_channel_bridge().

* Fix an unbalanced manager_bridge_event(unlink) call if
AST_SOFTHANGUP_UNBRIDGE is set in ast_channel_bridge().

* Make ast_channel_bridge() use common cleanup code when leaving the
bridge.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@378889 65c4cc65-6c06-0410-ace0-fbb531ad65f3