Release v0.0.1

• initial release, code moved here from https://github.com/wairas/happy-tools
• fixed exception in data-viewer when cancelling the open dialog
• fixed loading of initial scan/references happens now in thread launched from main loop
• changes in r/g/b scales of the envi-viewer no longer trigger image update when ignore_updates==True
• the set_wavelengths method of the envi-viewer no longer triggers image updates, but can trigger one after setting all values