Fix upgrade constants after removing AAF upgrade

Also, remove AAF upgrades on both sides, since the offsets apply to both sides,
so they cannot have different upgrade trees.
Merge pull request #17 from guido2/fix_upgrade_constants_after_aaf_removal

Fix upgrade constants after removing AAF upgrade
AGM modules and items added
Changed base buildings on both sides
Merge pull request #18 from MDTorch/agm

AGM modules and items added
Merge pull request #19 from MDTorch/structures

Changed base buildings on both sides
Increase difficulty in settings again
Enable Zerty Repair/Force-Lock again

Disabling it ended up disabling the interaction button
Merge pull request #20 from guido2/increase_difficulty

Increase difficulty in settings again
Added US Special Forces and Russian SPETZNAS weapons and vehicles
Merge pull request #21 from MDTorch/sfspeznas

Added US Special Forces and Russian SPETZNAS weapons and vehicles
Reduce resistence vehicles in sub 500 towns
Merge pull request #22 from guido2/reduce_vehicles_in_small_towns

Reduce resistence vehicles in sub 500 towns