- keyring: keyring/session identifier used by key manager
- keystore: choice of db/file key storage
- import message updated
- export: name of directory to export keys to (was bool)

- introduce gui.Stop()
- remember state with open
- stopping ethereum stack is not gui concern, moved to main
- stopping mining, gui and ethereum handled via interrupt callbacks
- ^C triggers exactly the same behaviour as quit via menu

- only add the gui logger after window is shown otherwise slider wont be shown
- need to silence gui logger after window closed otherwise logsystem hangs
- gui.GetLogLevelInt() extra function needed to give correcty int typecast value to gui widget that sets initial loglevel to default

fix logSlider: now has 5 levels, initialized to gui.GetLogLevel which is set through command line flag (defaults to InfoLevel)

You are welcome Stephan.

- 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