Raise ActionID and UniqueID variable sizes

[EPuncker]

My simple suggestion is to raise actionid and uniqueid variables from uint16_t to something else like uint32_t...

https://github.com/hampusborgos/rme/blob/master/source/item.h#L240-L244

for a long time already the very high fun exp ots were using very high levels, but recently even cipsoft already passed the 1k level mark and since the way we scripted doors used the "1000 - level" to calculate level doors, we can't easily do that because of the 65k limitation...

as seen here

[Silba93]

I think it's about time, yeah.