* 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
* common/compiler: solidity compiler + tests
* rpc: eth_compilers, eth_compileSolidity + tests
* fix natspec test using keystore API, notice exp dynamically changes addr, cleanup
* resolver implements registrars and needs to create reg contract (temp)
* xeth: solidity compiler. expose getter Solc() and paths setter SetSolc(solcPath)
* ethereumApi: implement compiler related RPC calls using XEth - json struct tests
* admin: make use of XEth.SetSolc to allow runtime setting of compiler paths
* cli: command line flags solc to set custom solc bin path
* js admin api with new features debug and contractInfo modules
* wiki is the doc https://github.com/ethereum/go-ethereum/wiki/Contracts-and-Transactions
