Started implmenting projectile
GTGProjectile: Added per-axis speed/acceleration and some accessors
GTGProjectile: Shoot rms from rms on space key
GTGProjectile: Added Reset()
GTGProjectile: Made x and y public
Make rms shoot projectile to the direction he's facing
Made projectile rms spin
GTGProjectile: Added cooldown
GTGProjectile: Fixed a bug that causes projectile to sometimes travel in the
wrong direction
GTGProjectile: Keep drawing projectile after cooldown