solidity compiler and contract metadocs integration

* 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

cmd/utils/flags.go

@@ -224,11 +224,17 @@ var (
 		Name:  "shh",
 		Usage: "Enable whisper",
 	}
+	// ATM the url is left to the user and deployment to
 	JSpathFlag = cli.StringFlag{
 		Name:  "jspath",
 		Usage: "JS library path to be used with console and js subcommands",
 		Value: ".",
 	}
+	SolcPathFlag = cli.StringFlag{
+		Name:  "solc",
+		Usage: "solidity compiler to be used",
+		Value: "solc",
+	}
 )
 
 func GetNAT(ctx *cli.Context) nat.Interface {
@@ -294,6 +300,7 @@ func MakeEthConfig(clientID, version string, ctx *cli.Context) *eth.Config {
 		Dial:               true,
 		BootNodes:          ctx.GlobalString(BootnodesFlag.Name),
 	}
+
 }
 
 func GetChain(ctx *cli.Context) (*core.ChainManager, common.Database, common.Database) {