Expand CJ to other biomes

[bloodydoves]

Persuant to a discussion on the BTA server, an issue is being opened to serve as a reminder.

We discussed the idea of opening up CJ to other biomes. The idea would be it would cause at least some ambush types on other biomes when buildings were appropriate (mostly capture/destroy base contracts). My vision of it is that it would mostly be for captures since when the player closes in to take the base, the base would fire back with hidden defenses (infantry, IEDs, even mech/tank makes sense because better we destroy it than let the enemy take it, etc).