Fix a few miscellaneous things

* Renamed some taskprocessor listener callbacks
* Fixed what would become a refcounting issue for pools
* Removed some XXX comments from allocation failure points



git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@377061 65c4cc65-6c06-0410-ace0-fbb531ad65f3