Fix aihDoesntMatter still being attacked with air attack
The calculation in TestBazooka created a sum of numbers which might have been BadTurn, a huge negative number, thus creating an overflow.
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
