ParameterValue has redundant hasMeasure property

[jakebeal]

ParameterValue has a hasMeasure property that duplicates that on its subclass, MeasureValue. MeasureValue should also be named value, like its siblings, rather than hasMeasure

[bbartley]

This is tricky, because value is defined as an owl Datatype property rather than ObjectProperty. Overloading it might cause some undesirable complications with the implementation.

[jakebeal]

I can see that the distinction between a simple property vs. an object reference could merit a different name. We can stick with hasMeasure then.

[bbartley]

Another possible solution could be to use multiple inheritance... MeasureValue could inherit from both om:Measure as well as opil:ParameterValue. While multiple inheritance is sometimes considered an antipattern, in this case it might simplify both the data model and the API.

[jakebeal]

I think we can leave this one while we consider #135 and #132, either of which is likely to render this point moot.

[jakebeal]

I'm going to split out the rendering part of the issue, however, which also affects other parts of the diagram.