Fix the popups handling.

Use wl_shell_surface_set_popup() instead of wl_shell_surface_set_transient(),
since the latter is not supposed to make the surface follow the transient
parent movements.

Needs Weston master or 1.0.6, otherwise freezes will happen.
To have the best experience you should however use recent weston master.
The popups in QtCompositor are badly placed.

Change-Id: I3c86e5d74503514749840681b4e81c58cd73ca70
Reviewed-by: Andy Nichols <andy.nichols@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>
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
Reviewed-by: Andy Nichols <andy.nichols@digia.com>
make failure to configure wayland non-fatal for a top-level build of qt

Change-Id: Ibd0557158ffa00cbacd64b4780961a684ab40afb
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>