Add Remington 870 to game

[bjincy]

After conferring with other staff, we would like the 870 from FAS:2 (the weapons pack already used) to be added to the game on a trial period. The spawn rate should be the same as the m-82 for now, and can be adjusted based on its performance. it should come with 12-16 shells (1 1/2 to 2 clips of ammo). After using it in various ways on single player, it is my belief that it will not be overpowered, but will add a new element to the game, hopefully keeping people moving in town and factory instead of camping.

[AOBatch]

Every gun spawns with 2 clips of ammo but yes i'm down. Also Mac10 pls