Optimize Zthuee projectiles (amongst other projectile things)

[Garanas]

Our benchmark is 400 Zthuee firing at once on the map White Fire. The map has no civilians. All functionality of the original projectile is still there, just faster. A base line is the same scenario, but without the Zthuee firing.

On the FAF branch: 12 - 14 ms with a base line of 3 ms

This pull request: 9 - 12 ms with a base line of 3 ms

This pull request, without decals: 9 - 10.5 ms with a base line of 3 ms

If we'd reduce the base lines:

• FAF branch: 9 - 11 ms for firing
• This pull request: 6 - 9 ms for firing
• This pull request, without decals: 6 - 7.5 ms when firing

Therefore we can safely assume that there's at least a 20% performance improvement. Some of these changes apply to all projectiles.

[Garanas]

Ran tests on several games, all appears to be good.