Resize breaks the sdl window in some cases

Merged Mads Buvik Sandvei requested to merge madsbuvi/openmw:resize_breaks_window into master

While working on !262 (closed) i encountered this bug. Ref: issue #5539 (closed)

When resizing a smaller window to the full size of its display, some display managers will automatically maximize the window. This moves the window to the top left corner of that display. SDL does not appear to handle this case and just breaks if the window was not already in this corner. This workaround fixes this by explicitly moving the window to the top left corner when such a resize happens.

Edited by Mads Buvik Sandvei