Added unknown 0x04 and 0x0F block placeholders.
More redesign of metadata
Added HasQuantifiableSupply interface for more abstract accesses.
Removed unneeded class. (benign code-breaking will result)
Moved ProjectilBehavior to its own class.
Implemented new types of Projectile objects.
Implemented ProjectileFiringBehavior which will auto-upgrade on powerup
(for lasers)
Final propagation of Powerup redesign using enum metadata.
Kludge: Mitigated flickering explosions bug.