The destroy member in wlr_keyboard_impl has been removed. The function
`wlr_keyboard_finish` has been introduce to clean up the resources owned by a
wlr_keyboard.
`wlr_input_device_destroy` no longer destroys the wlr_keyboard, attempting to
destroy a wlr_keyboard will result in a no-op.
The field `name` has been added to the wlr_keyboard_impl to be able to identify
a given wlr_keyboard device.
This introduces -DWLR_USE_UNSTABLE and adds information regarding the
stability status to all headers. I started with a conservative set of
headers to mark as stable:
- types/wlr_matrix.h
- util/edges.h
- util/log.h
- util/region.h
- xcursor.h
