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

ethereum/cmd.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+  "github.com/ethereum/eth-go"
+  "github.com/ethereum/go-ethereum/utils"
+  "os"
+  "io/ioutil"
+)
+
+func InitJsConsole(ethereum *eth.Ethereum) {
+  repl := NewJSRepl(ethereum)
+  go repl.Start()
+  utils.RegisterInterrupt(func(os.Signal) {
+    repl.Stop()
+    ethereum.Stop()
+  })
+}
+
+func ExecJsFile (ethereum *eth.Ethereum, InputFile string) {
+  file, err := os.Open(InputFile)
+  if err != nil {
+    logger.Fatalln(err)
+  }
+  content, err := ioutil.ReadAll(file)
+  if err != nil {
+    logger.Fatalln(err)
+  }
+  re := NewJSRE(ethereum)
+  utils.RegisterInterrupt(func(os.Signal) {
+    re.Stop()
+  })
+  re.Run(string(content))
+}