More vehicle stuff (CR)

Added Mark 19 Grenade Launcher and fixed the APC so it was more of an
APC and less of an armored bus. Plans to add Electrified Hull Plating,
Impact Resistant Hull Plating (For plows), and set up turrets to not
blow up their own vehicle. Also added M2 Browning and Mark 19 to the
bunker heavy weapons spawn.

It's not done yet.