ecere/gui/XInterface: (#850) Fixed unmaximizing issue on GNOME Flashback (Metacity)

ecere/gui/XInterface: (#850) Fixed unmaximizing issue on GNOME Flashback (Metacity)
- Fixed absPosition of menu bar not being set to proper value after unmaximizing
  through dragging window on GNOME Flashback (Metacity)
- This was causing menu bar to not be redrawn / processing clicks properly
- Passing value of 'unmaximized' to 'force', which was previously changed to false
  by f3ece7c9aaada43876cb424132b7f56259033a9a (avoiding forcing on stacking only changes)
- A fix for a seemingly similar problem on Unity ( 85ad13a7fd22eae3ed60f29ff69c912635a97dfb )
  may have contributed to this problem, as it prevented resetting the root window state