Projectiles should penetrate entities as long as they still have kinetic energy

[ymber]

Is your feature request related to a problem? Please describe.
.50 BMG rounds are stopped by 3mm sheet steel. This shouldn't happen.

Describe the solution you'd like
Projectile overpenetration should be modeled. If we define initial energy for a projectile this value can be used to derive damage and can be reduced every time it goes through something by an amount derived from the object's properties. Handling deflection and such will be harder until we have velocity and force vectors implemented for projectiles but we could just add dispersion for everything the projectile penetrates.

Describe alternatives you've considered
Implementing error vectors for our sum of errors dispersion system first.