[oslc-core] Drop oslc:describes from oslc:ResourceShape

[Dave]

I'd like to raise this issue for discussion. Here's the description:

Resource Shapes - #25 - OPEN - We do not want to enable rigid schemas
and we're not convinced that Resource Shapes are useful beyond
resource creation, query and possibly a constrained form of update.
So, we should not tie shapes to types and theoslc:describes property
should be removed from the oslc:ResourceShape class (DaveJohnson,
06/14/2010).

Do we have any use cases that depend on oslc:describes? Anybody object
to dropping this property?

Thanks,
- Dave