Removing TestConnection, Starting fixes for AsyncServiceClient

Fixes #13 .  This totally removes the crappy TestConnection I wrote a while ago that uses blocking sockets, and now just uses an AsyncServiceClient.  Some tests are still ignored because of #19 , and the test referenced in #4 just needs to be redone.
Refresh my memory, this change was needed for that additional "stash" invocation, right?  We were in a state where we were not getting certain messages?