ACF7: Add one pick hammer in crate
Players often reported to screw up with the pick hammer, which is quite annoying.
With one pick hammer more, this mission should be slightly less annoying.
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
