This is completely unnecessary.

The former was broken in a previous commit, the latter is now properly
introduced (as shaded windows still report the same geometry, we handle
them as we do fullscreen windows - not).

Should also fix e.g. Firefox resizing.

This removes any remains of the idea of a "floating tile".
We're not a window manager, we just need to care about tiling windows.

This only does one simple special case for the spirallayout (two clients on screen).

This also fixes a bug with tiling because a method was missing.