milestone-A (0.9.2.1)

Milestone A is the first milestone since the move to github.

It is meant as a maintenance release, "let's polish and release what we have now".

• New UI compared to milestone-9 (actually, the UI was fully overhauled twice)
• UI is more polished: all in-game dialogs have 'skins'
• More languages and more things (e.g. object tooltips, levels) are translated.
• Much more levels - but we need to test if all levels still work
• Automated testing of various levels to ensure that the games runs the same on all platforms
• Disabled level editor - it is too broken to release