Hero Projectiles

Hero Projectiles should now allow modification of damage dealt, whether
or not the projectile will disappear on contact with an enemy, movement
speed. Enemies now have similar hit checks to players, but for hero
projectiles. This allows us to set enemy flinch frames/invincibility as
we see fit.
Also, our hound can be attacked and will despawn when current health
falls to or below 0.

Currently, a maximum of three shots can be on screen at a given time,
although this could be configured on a weapon by weapon basis if we
wanted to.