shell: Add possibility to move surfaces to other workspaces
shell: Add possibility to move surfaces to other workspaces

By default, Control + Shift + Up/Down will move the currently active
surface, if any, while changing to another workspace.

Signed-off-by: Jonas Ådahl <67dcd8a17e758192e0cbb577ce1d62cc7da6cf49@gmail.com>

xorgy/weston,Gnurou/weston,mchalupa/weston,krezovic/weston,giucam/weston,jonnylamb/weston,mchalupa/weston,Gnurou/weston,Tarnyko/weston-xdg_surface_present,krezovic/weston,xorgy/weston,kwm81/weston,eyolfson/weston,kwm81/weston,giucam/weston,Tarnyko/weston-xdg_surface_present,sir-murray/weston,sir-murray/weston,Fantu/compositor-spice,eyolfson/weston,udoprog/weston,udoprog/weston,Fantu/compositor-spice,jonnylamb/weston,Fantu/compositor-spice