shell: block move, rotate, resize in maximized state

To remain consisten with client side window, which blocks moving and
resizing of window in maximized state, we should do so on the compositor
side as well.
shell: reset rotation for maximized surface

Surface will preserve its rotation transformation when maximizing, which
will cause incosistiencies (eg. no window shadows drawn)

This patch removes rotation from maximized surface and restore it when
unmaximizing (just like in fullscreen mode)
window: save allocation only for toplevel window

Thanks to that we will not overwrite saved allocation, when going
fullscreen from maximized state
window: restore maximized state from fullscreen mode if necessary

This patch sets back maximized mode, if that was its state before going
fullscreen.
compositor-drm: Inspect result of gbm_create_device.
Merge branch 'fix_maximize' of https://github.com/rafalmiel/weston into next