* 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: http://svn.asterisk.org/svn/asterisk/trunk@378889 f38db490-d61c-443f-a65b-d21fe96a405b