Made small adjustments to test weapons
Changed LinearMotion to support "pass through"

This allows projectiles to move in one direction without affecting the
other axis. So it's good for things like the top since it's gravitated
but also moved along the X axis.
Adding additional properties to projectiles
Moved "aging" up into Entity, updated affected classes

This allows projectiles to die after a certain amount of time.
Only trigger water event when plunging (entering)