Wayland: Improve compositor compatibility by allowing older globals

Previously we pretty much hardcoded most of the globals we requested,
causing compatibility issues with certain compositors like Weston, which
support only some pretty old versions or miss some more advanced
protocols.

To put fuel on the fire, we also errored out when certain protocols
weren't available, despite us being able to boot a game just fine (but
obviously with a degraded featureset).

The solution is to simply allow all the way from version 1 to the
current latest, adding some compatibility code (such as for older
`wl_output`s or newer `wl_pointer`s).

While we're at it, this commit also fixes a few typos and naming inconsistencies
I found.