Engine: * Fixed aiming for Ballgun and Flamethrower

Engine: * New weapon attributes: ejectX/ejectY: Offset to the hedgehog (center of hand graphic) where the projectile(s) will be spawned * Changed Laser Sight to origin from the weapon instead of the hedgehog (needs some adjustments while walking/jumping) * Changed most weapons to no longer shoot from the hedgehog's center and use the weapon's visible position instead (might require some testing and adjustments) * Silenced the small Piano explosions

Engine: * Added some animation to Vampirism's hand graphic

Engine: * Updated Flamethrower's hand graphic and added some animation

Prevent all portal loops the guaranteed way, at least until sheepluva's tests yield something reliable.

initial support for game modifiers (schemes)