New Update fixes stuff

Hello again,

here, have some more fixes. Last time I said I won't maintain this game anymore, but then I realized there are still some ugly issues hidden inside which passed my One-Man-Testing-Team unnoticed. So here it is - another bugfix release. Again only Windows and Linux, MaxOSX is in the works.

• fixed Arcade Mode hiscores submitting correctly again
• fixed possible stuck keys on exotic controllers blocking the game
• disabled automatic switch to gamepad controls
• Alt+Enter now switches between Windowed and Fullscreen at any time
• renamed config variables for resolution to make fiddling with them easier
• updated GLFW to 3.1.2 which claims to bring a lot more workarounds for buggy window managers on Linux
• repaired concurrent operations which makes Savegames super-smooth again, for example.