This reverts commit 2396aec684.
This exact version of the sub-surface protocol has been copied into
Wayland core. Therefore it must be removed from here to avoid build
conflicts and useless duplication.
No other changes to sub-surface protocol consumers are needed, the
identical API is now offered by libwayland-client and libwayland-server.
The commit adding sub-surfaces to Wayland is:
Author: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
protocol: add sub-surfaces to the core
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>