new window positions top left, top right, bottom left and bottom right
these new maximized positions are combinations of left, right, top and
bottom maximized positions
if a window was at x=0 or y=0, the original condition return
false and the window is not moved to original position,
but if width or height from old_geometry is set then wmaker
already saved old_geometry, and we can trust x=0 or y=0 is
original position.
Renan Traba