[SPEC-CHANGE] Mandatory scheme in request and link URLs

[Waweic]

> Oh, gosh darn it.  I obviously didn't mean to do that.  This is what
> I
> get for trying to squeeze spec changes into small slices of free
> time.
> Sorry, everyone.  I will fix this tomorrow.

I think the actual change in the spec is fine, it doesn't disallow
relative URI References, (called Relative URLs in the spec, which
should be changed imo) it even explicitly allows them. Assuming a
scheme of gemini:// (which was removed) would be wrong, since a
text/gemini document could be accessed via other protocols.

So, apart from the URL / URI / URI Reference stuff, I think the spec is
on point here