Some axioms added

Just a couple of them, but I think they can be useful.

This is not the final version, but I couldn't think of a better place to store this version before messing it up.
Some more axioms added

Not causing loops yet.
Create q10.sparql

it could be interesting to use an instance instead of [a cf-feature:Humidity]

Easier said than done.
Update sensordemo.owl

more minor updates
Merge pull request #1 from jmora/patch-1

q10 and ontology changes accepted