Destroy input resources.
Remove compositor_free function as we need event loop and handle the
cleanup gracefully ourself.
Check that output has renderer and remove unused include.
Static analyze fails to detect this case.
Implement more of xwm's destruction and do not overide dl handles.
Store surface id before calling link_surface as it may release the x11
window.
Restore original crtc mode.
Check valid fds to revoke.
Close all open fds on quit.
Handle drm fds. This makes TTY switching work.