Make MCV crush infantry
Grenade slightly faster again. 100% vs. none.

After playtesting, it seems the grenade is a *bit* too slow. Keeping it slow, but bringing its speed from 5 -> 7. (Original value was 12)

Looks reasonable.

Also giving 100% vs. infantry instead of 90%.
Reducing spread of GrenadierExplode

GrenadierExplode is a good idea, but right now its damage is too high.
Reducing spread from 8 -> 6.
Small buff for Humvee/buggy machine gun

Machine gun seems to be under-performing vs. infantry
Give it 5 bursts instead of 4. Will allow it to kill E3s more effectively.

Despite this change, overall damage vs. Light armor is not increased since Release.
Merge pull request #5212 from psydev/patch-1

Some minor tweaks