YARN-679 test for service launch
YARN-679 test for bindArgs operations
YARN-679 add AbstractLaunchedService base class for launched services, tests to verify that a subclass of this rejects arguments -but doesn't reject --conf args as they are stripped
YARN-679 exception throwing/catching in execute
YARN-679 verify that constructor inits are handled
services that only have a (String) constructor are handled by giving them their classname as a name
YARN-679 optimise imports