* removed unneeded bc->state field

* added statefullness for bchannel activation/deactivation
* fixed a lot PCM bridging issues
* some debugging logs are now on a higher loglevel



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@17128 65c4cc65-6c06-0410-ace0-fbb531ad65f3