Added additional RPG for RATs

*All RPG-32 RATs (AAF, FIA, CSAT) now carry one additional RPG-32 on "medium" and "heavy" loadouts for a total of 2/3.
* Fixed comments in assignGear_backpack files which still referring to the old "backpack" parameter.
Merge pull request #436 from Wolfenswan/dev-RATmags

Added additional RPGs for RATs