Speed up creature pickup/drop/marking tiles/build room/build trap

@Bertram25 @akien-mga Please test a little bit more this one as usual because I changed some sensible stuff (see details in the commit). But it seems pretty stable as I let the game play alone during 3 hours and I had no crash (I stopped it turn 12517). I also tried quitting the mission and restarting it and fixed the related bug I've seen (mostly about treasury room)
fixes #103