We can (again) check for updates and, if an update is available, send
the user to the site to download them.

The old format (a .json specifying a version number and download URL)
was kept. The address for this file is now specified in the settings.

We can (again) check for updates and, if an update is available, send
the user to the site to download them.

The old format (a .json specifying a version number and download URL)
was kept. The address for this file is now specified in the settings.

Mostly, removal of old code that had been commented out instead of
removed

Desktop mode is broken
SANKORE-633
Positioning of floating palettes inside layers .

* Fixed screens initialization order and logic.

checking if internet is available before trying to check for an update. This resolve the shutdown after a minute error on mac os x and windows