The test genesis block was not written properly, block insertion failed
immediately.
While here, fix the panic when shutting down "geth blocktest" with
Ctrl+C. The signal handler is now installed automatically, causing
ethereum.Stop to crash because everything is already stopped.
* resolver -> common/registrar
* global registrar name registry interface
* add Call to resolver backend interface
* the hashReg and UrlHing contracts now initialised from global registry
* initialization of contracts uniform
* improve errors and more econsistent method names
* common/registrar/ethreg: versioned registrar
* integrate new naming and registrar in natspec
* js console api: setGlobalRegistrar, setHashReg, setUrlHint
* js test TestContract uses mining - tests fixed all pass
* eth/backend: allow PoW test mode (small ethash DAG)
* console jsre refers to resolver.abi/addr,
* cmd/geth/contracts.go moved to common/registrar
