Use more stuff from ECM and require gcc >= 4.8
Use imported targets for declarative plugin too
Temporarily exclude update cursor code
Add fullscreen shell protocol file
Fix client kill when surface is unresponsive

Upstream I manage to add the client property to surfaces, that object
has close() and kill() methods.  Let's use kill() here to kill
the client once and for all.
Set parent position when the global geometry has changed

Fixes window move grabbing.
Add initial and non functional global shortcuts manager

This is just a class that inherits from the keyboard grabber,
it will need to read shortcuts from kglobalaccel and decode
keyboard events.
Add xdg-shell support

Initial support for xdg-shell v4.
xdg-shell: Add a custom move surface operation

Code to move windows is now in a dedicated function that is shared by
the new Move surface operation and the move request from xdg-shell.
Add wl_shell and wl_shell_surface protocols

QtCompositor already support these but we need our implementation
to properly handle window move and multiple outputs.