OWL Lite semantics

In the current semantics draft, OWL Lite just gets the same semantics as OWL
DL on the syntactic subset.
It would be possible in our one-dimensional layering to give OWL Lite a
reduced semantics.

This has the following advantages:
- clearly differentiation between the two
- much easier to implement OWL Lite so it really becomes an entry level

I attach a modified version of section 5 of the semantics doc that changes a
few iffs to if-then's, and drops comprehension.

As far as I can tell, teh vast majority of the entailments discussed in the
feature synopsis under OWL Lite are preserved, at much easier
implementability.

Also we can add hasValue without any difficulty.

It permits a conformance statement, in a subsequent e-mail, that has no
leeway, but is truely Lite.

Jeremy