Fixes #2: Add facility to distinguish devices

The service object "tabris.Device" object got these new properties:
  - vendor (String)
  - model (String)
  - osVersion (String)
  - scaleFactor (float)

The service object "tabris.App" got these new properties:
  - tabrisVersion (String)
  - id (String)
  - version (String)

Change-Id: I240b35c832ef66b8a69a66bd1f76cabb5a73fce5
Merge "Fixes #2: Add facility to distinguish devices"