Split mod (game) logic into pluggable minimods

[demoth]

Quake 2 mods are developed and distributed as one big chunk of logic, combining monster/weapon/item/coop/deathmatch rules, etc..

There are however many parts of the mod that don't interact with each other (like monster logic and weapon logic) and therefore could be isolated. Both code and resources.

This is just and idea and need more refinement