assetPath configurable on command line for ethereal GUI

- solves the problem of non-standard installs
- add AssetPath to config as string var
- introduced UiLib constructor which falls back to defaultAssetPath (earlier behaviour) if no assetPath is set
- defaultAssetPath now internal concern of UiLib
- gui.Start(assetPath) argument passed from ethereal main() as set Init() in config.go
- informative log message if wallet.qml fails to open

Conflicts:
	ethereal/Makefile

The Ethereum node and Gui are now separated.

when building develop branch, checkout of eth-go develop branch is required

QML files got moved to their own directories. QML now has a ui helper
which should find assets in the correct resource directory

Search bin directory for qml