improve testutil's BaseRequestTestCase
improve testutil's BaseRequestTestCase

In this change we're doing a couple of things:
* removing the DNS hostname check, we should just
  let the request fail instead
* Move the url check into setUp() so it's not
  performed at startup
* If the configuration does not define a url, don't
  run the tests that require the url
* Set a timeout on the socket so we don't sit there forever

guidow/pyfarm-agent,guidow/pyfarm-agent,pyfarm/pyfarm-agent,pyfarm/pyfarm-agent,guidow/pyfarm-agent,pyfarm/pyfarm-agent