Updated assignGear files, groupMarkers, and missionConditions

Updated assignGear_US and assignGear_us_b with better/debugged gear.
Updated groupMarkers to add SL and M1, M2 markers for each squad; also
added Delta, Echo and Foxtrot squads (in 12-man squads). Gave each squad
a unique color. Did a little messing with missionConditions.