skypiax: patch from Seven Du for hunting IDLE channels in a round-robin way (RR interface vs ANY interface). patch from Seven Du for removing interface as #'interface_id' and #'interface_name'. gmaruzz (meh) patch interface_remove() not to alter the global 'running' variable (it would cause all running signaling and API thread to exit) but to use a newly added tech_pvt->running variable. Also, changed behavior of interface_exists() for correct identification when using #interface_name and #interface_id. PLEASE TEST IT HEAVILY

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@14410 d0543943-73ff-0310-b7d9-9358b9ac24b2