destroyCaches - spawn marker vehicle

Spawn an empty truck near the weapons cache to make locating it easier.
DestroyCaches - more variety + difficulty

* Spawn an additional patrol for each ammo cache that exists
* Up the difficulty by 1 from default (at least 2 caches now)
* Add some variety to the guards (either urban guards or an officer w/
light inf)
* Add some variety to the vehicle parked nearby (all CSAT transports or
unarmed ifrit)