Remove zombie state from threadpool altogether.
After giving it some consideration, there's no real
use for zombie threads. Listeners can't really use the
current number of zombie threads as a way of gauging activity,
zombifying threads is just an extra step before they die that
really serves no purpose, and since there's no way to re-animate
zombies, the operation does not need to be around.
I also fixed up some miscellaneous compilation errors that
were lingering from some past revisions.
git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@377211
65c4cc65-6c06-0410-ace0-
fbb531ad65f3