Small GUI Improvements

[gituser789]

Describe the solution you'd like

• Add Help-menu
  -> 'Help': Link to 'User-Manual'
  -> 'Version number'
  -> 'Check for Updates'
  -> 'Report Bug' -> Link to github issue page
  -> 'Contribute' -> Link to github page
• Also show the version number in the title of the window. This will be very helpful, escpecially at the early days of the GUI.

[gituser789]

Best is to search for updates at startup and give a hint if updates are available including download-link.

[gituser789]

General idea for dealing with version numbers: pbr-package, see comment in this post
https://stackoverflow.com/questions/458550/standard-way-to-embed-version-into-python-package