Mutant: Force special mutant/feeder hat+name to be only hold by those who deserved it
Previously, a player could just name their hog "Mutant" and give
it the respective hat to try to confuse other players. This is
no longer possible.
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
