Custom pickups detectable via ON_CONDITION

[Lobo]

The only way to be able to track certain actions globally in RTS is by using one of the extra ammo types as a counter i.e. for currency or point systems, mission objectives etc.

Ideally we wouldn't have to do things this way if we could:
(1) allow creating custom pickups which could be used for counting instead via ON_CONDITION.
(2) define a global variable that keeps count across all scripts.