Update WorldToMinimap code for minimap positions

New code causes much less shift of object positions as you get further
from them.

Comment 1: Should be 45 degree rotation, why does 45 look bad as you get
further from the object (precision?)  Tried many values and 40 seemed
stable.
Comment 2: Should be X=cosX + sinY, Y=-sinX + cosY.  Doesn't work that
way, only works with current format.  Why??