surface: clear buffer instead of role on null attach

surface: Clear role on null attach

Change arg to be command to run

Scroll support

viewporter: Add support

ui: Add space-to-fold

pointer: 'focus' -> 'entered'

surface: More compact layout

Track buffers

Add missing wl_output.go

Fix key/button held count

Fix subsurface state related crash

Track wl_outputs

Show xdg_toplevel surface state

Print surface and parent

Move role debug to implementations

xdg_shell: Hack up xdg_positioner support

Change to vim-style quit

Expand readme

Update readme link