Commit some progress towards threadpools.

Does this compile? Not even close.
But I figure I don't want to lose this all in the case
of some catastrophe.



git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376833 65c4cc65-6c06-0410-ace0-fbb531ad65f3