Improved feature limits interval hook implementaion.

* Fixed feature limits to not use special members of struct
ast_bridge_features.

* Fixed memory leak in off nominal paths of bridge_builtin_set_limits().

* Fixed off nominal path in ast_bridge_features_limits_construct() freeing
unallocated memory if it was not called by bridge_builtin_set_limits().

* Made bridge_builtin_interval_features.so unloadable.

* Simplified parking's use of its duration interval hook.

* Made BridgeWait S option not depend upon another module being loaded.

(closes issue ASTERISK-22107)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/2701/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@395559 f38db490-d61c-443f-a65b-d21fe96a405b
Remove the unsafe bridge parameter from ast_bridge_hook_callback's.

Most hook callbacks did not need the bridge parameter.  The pointer value
could become invalid if the channel is moved to another bridge while it is
executing.

* Fixed some issues in feature_attended_transfer() as a result.

* Reduce the bridge inhibit count in
attended_transfer_properties_shutdown() after it has restored the bridge
channel hooks.

* Removed basic bridge requirement on feature_blind_transfer().  It does
not require the basic bridge like feature_attended_transfer().


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@395574 f38db490-d61c-443f-a65b-d21fe96a405b