The shield and bow both use fx.aim_weapon, but the ranged weapons AI thinks that a shield works the same way as a bow and tries to fire it - in order to prevent this, the AI now also checks whether the equipped item is a IsRangedWeapon. This _could_ have an impact on the vehicle AI, but the unit test worked fine.
A single player now receives four times more wave bounty than before, scaling up to four players. It's still challenging but I believe now doable.
Enemies should no longer jump off airships when being shot at.
Fixed a typo in the airship appendto script.
Fixed a possible null pointer when changing weapons.
Removed the windbag from the chest (might also remove it from the buy menu).
The chest below the base will now sometimes contain a gold bar, giving extra money to the player picking it up.
Made sure that no airship remains after fade out.