This reverts commit df56628979abc17474b001c58c28c6f3637ada9d.

It causes an issue where windows remain in the background even when
being drawn in the foreground.

By scaling the pixbuf when loading, existing assets can be used.

Adding a new option to allow tile size cycling. When enabled, using the
keyboard shortcut for tiling multiple times in a row cycles the window
through different sizes (1/2 -> 1/3 -> 1/4 -> 3/4 -> 2/3 -> Untiled).

find . -name "*.png" -exec mogrify -strip {} ;

Since we're rewriting how tab popups are created, we should change the
gschema value ranges so that they are more compatible with the new
version.

When drawing the workspace switcher OSD, we want it to be slightly
transparent to match the OSD style. Also changed how the popup size is
calculated and changed window icons to cairo surfaces.

Instead of converting from surface to a GdkPixbuf and then back to
a surface, we keep it as a surface for the entire manipulation flow.
This improves rendering speed a bit and sets the ground for a higher
resolution thumbnail in the future.