Merge pull request SINTEF#41 from SINTEF/update-readme

Added definition of iri, uri, url and uuid to the vocabolary in the README.

Allowed property dimensions to be specified like ["N+1", "N-M"] where

"N" and "M" refer to the dimensions of the instance.

Also cleaned up the code generation and reduced name collisions between
internal fields and dimension and property names.

Fixed version number

Increased version number to 0.2.1

0.2