Scene details shorter, widgets work, listen service fix
* Listen Service fixed
* Widgets use a Widget Update Service
* ShortcutExecutionActivity updates widgets if necessary
* DevicesUpdate Interface for adapters (un/registerDeviceUpdate)
* New mechanism for requesting a device update and get informed on
  that update or get a timeout
* New data structure: DeviceCommand. Build from OutletCommandGroup
  which is good for storing on disk but not for creating the command udp packet.

Still missing / bugs:
* Save scenes and configured devices as json files
* NFC
* Testing