Fix hwengine crash when using >1 controllers
Reason: Data type mismatch for SDL_JoystickName, we wed in an index, but it expected a controller handle.
Solution: Switch to SDL_JoystickNameForIndex.
07f3bf8d98a3
Hedgewars.png had a resolution more than twice as high as required; also fixed some (mostly obsolete) code that also contained a typo that would cause a warning/note in clang
