Include groovy only in ‘compile’ scope.
Add some more BitcoinJ tests
First accurate, balance-verifying RegTest tests

* Requires Faiz’s changes in add-regtest- branch
* TestSupport trait with createNewAccount() and createFaucetAddress()
* Using MastercoinClientDelegate with @Delegate annotation, again
* Remove some unneeded “throws IOException” declarations
* Misc other cleanup