Install qwayland-server-wayland.h

It's required by the private QtCompositor API.

Change-Id: I2f00fb5f60e5b849bb9656deef998ef3a1fb26e4
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>
Attach always the front buffer before committing it.

The attach semantics changed in Wayland master.

Change-Id: I79efa5e3b2d048604cadb18543101a869ccb6835
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>