Remove ThreadLocal clearing.

Since it is of little value, and only prevents undeploy memory leaks for very
simple applications. It's a workaround for a bug in clojure that will hopefully
be fixed in 1.6.
Don't involve the runtime when invoking the tx callback.

Since we no longer try to clear thread locals, we don't need to do
this either.  Calling through our runtime bridge breaks tx's when used
in threads that are wholly managed within the clojure runtime.
Restore tests after ThreadLocal fix and remove some old debug