Summary of cert : key Domain discussion

Summarizing the thread.

I proposed that the Domain of : key be more general than Agent, since a
public key is just a number, more than just an agent could have such a
key.  An example I gave was that an account (e.g. belonging to an agent)
could have a key pair.

Henry raised the point that you would then lose an inference that the
subject of a key was an Agent.  However you should really use rdfs : type
for this imho.

Henry also raised the point that it would be possible to construct triples
such as the eiffel tower having a public key.  Unsure if this is a big
deal, or even a demerit :)

There was a small straw poll which was pretty evenly balanced, slightly in
favour of keeping the status quo.

If there's further interest in this I'll raise an issue at some point.  But
I think I have enough to model what I want to now.