MarkMenuButton: discriminate gametypes internally

improves consistency and eases improvements
MarkMenuButton: renamed parameter for clarity
EventMgr::MouseDown: avoid a crash

guima has a window closer bound to doubleclick, which closed more
than it should
WorldMap: made map icon recoloring optional, as only bg1 needs it

fixes hideous iwd and pst map icons
Merge pull request #14 from chilvence/fixesonly

Dead: Make sure to append _DEAD to the actor name when checking kaputz
Activate dialog on clickable infopoints for torment