Feature/desktop

[jvolker]

This is the first step towards a version for other operating systems like Ubuntu (e.g. running on Electric Objects), and it also enables running Openframe on Raspberry Pi 4 with rotated screen.

This could also have other advantages:

• Quicker loading times for X server based extensions (like Website or Processing)
• It’s harder to get locked into command-line for new users who don’t know Linux / Raspberry Pi that well. Less confusion about Openframe not working in desktop mode.
• Quicker development right on the Pi in desktop mode

Disadvantages may be:

• Slower in some cases (especially extension not necessarily needing x server) compared to running in the command line. We haven’t tested what the difference in performance it’s really going to make.

More info here: https://openframe.discourse.group/t/desktop-mode-version-of-openframe/126

Tested in desktop mode or Raspbian on Pi4B.

TODO:

• compatibilty to command line mode
• fix tests