Mercenaries Single Use to be Enforced

It is a bit more work on my end. But mercenaries in the event were always meant to be single use. Regardless if they die or not they are to be used up. Replacements at the start of the turn will be give. @xInVicTuSx will be bugged more often to replace the merc groups. This should help address powerful mercs from being available for multiple turns. @Jobs update calc to indicate if a merc is used to be put into the lost assets list.

I will make them in larger batches so you can replace them quicker without having to rely on me as often.