The editor MP calculation with the action combining system needs refactoring

[hhyyrylainen]

as the system is way too complex to use correctly. I've just spent this week like at least 5 hours fighting the system, and this isn't the first feature that has such a problem.

I just think the whole system needs to be scrapped as it is way too hard to use. And I haven't seen the other programmers really to even try.

My idea is that we get rid of the minimum action combining logic and instead make it so that all action data itself is asked how much MP it costs given a history of actions. That way actions can inspect the history themselves and determine if they should give any discounts. This results in more manual code in each action type but gets rid of the really unexpected action combining system that I cannot seem to wrap my head around.