refactor cli and gui wrapper code. Details:

- all cli functions shared between ethereum and ethereal abstracted to utils/ cmd.go (should be ethcommon or shared or sth)
- simplify main() now readable stepwise
- rename main wrapper files to main.go
- rename commmand line args definition file from config.go to flags.go
- rename Do -> Start to parallel option names
- register interrupt for rpc server stop
- fix interrupt stopping js repl and ethereum
- register interrupt for mining stop
- custom config file option from command line
- debug option from command line
- loglevel option from command line
- changed ethutil.Config API
- default datadir and default config file set together with other flag defaults in wrappers
- default assetpath set together with other command line flags defaults in gui wrapper (not in ethutil.Config or ui/ui_lib)
- options precedence: default < config file < environment variables < command line

ethereal/ui/ui_lib.go

@@ -29,9 +29,6 @@ type UiLib struct {
 }
 
 func NewUiLib(engine *qml.Engine, eth *eth.Ethereum, assetPath string) *UiLib {
-	if assetPath == "" {
-		assetPath = DefaultAssetPath()
-	}
 	return &UiLib{engine: engine, eth: eth, assetPath: assetPath}
 }
 
@@ -88,6 +85,7 @@ func (ui *UiLib) ConnectToPeer(addr string) {
 func (ui *UiLib) AssetPath(p string) string {
 	return path.Join(ui.assetPath, p)
 }
+
 func (self *UiLib) StartDbWithContractAndData(contractHash, data string) {
 	dbWindow := NewDebuggerWindow(self)
 	object := self.eth.StateManager().CurrentState().GetStateObject(ethutil.FromHex(contractHash))
@@ -111,29 +109,3 @@ func (self *UiLib) StartDebugger() {
 
 	dbWindow.Show()
 }
-
-func DefaultAssetPath() string {
-	var base string
-	// If the current working directory is the go-ethereum dir
-	// assume a debug build and use the source directory as
-	// asset directory.
-	pwd, _ := os.Getwd()
-	if pwd == path.Join(os.Getenv("GOPATH"), "src", "github.com", "ethereum", "go-ethereum", "ethereal") {
-		base = path.Join(pwd, "assets")
-	} else {
-		switch runtime.GOOS {
-		case "darwin":
-			// Get Binary Directory
-			exedir, _ := osext.ExecutableFolder()
-			base = filepath.Join(exedir, "../Resources")
-		case "linux":
-			base = "/usr/share/ethereal"
-		case "window":
-			fallthrough
-		default:
-			base = "."
-		}
-	}
-
-	return base
-}