This fixes regression CORE-16289 where we could not longer
move the taskbar at a different than default location,
as WindowSnap would interfere.
Many Thanks to the patches author Doug Lyons.
Eventually the heuristic that we use here to identify the
taskbar via used window-styles could be improved later.
Theoretically possible that it bails out on some other windows.
The regression was introduced by 0.4.12-dev-373-g
7e396787ed
Implemented the following actions: stick the window on the left/right or maximize it,
with the following shortcuts:
- Win key + Arrows;
- drag to left/right screen border;
- double-click on top/bottom.
CORE-12845
