We don't necessarily need `wl_output.release`, which is the only
addition in v3.
This allows Looking Glass to run on Ubuntu 20.04 without having to go
difficult lengths to acquire newer Wayland packages. Since 20.04 is an
LTS release, this seems worthwhile for the small amount of complexity
this introduces.
Fixes
https://forum.level1techs.com/t/latest-build-allow-inhibiting-shortcuts-dialog-ubuntu/168684/6.
If the scale factor of an wl_output changes while the client is running,
the maximum scale factor is not updated. This may result in incorrect
scaling.
Therefore, when the scale factor is changed, we should generate a
resize event.