Deduplicate the Datatype Property declarations

[rhohimer]

When the stix.owl ontology was divided into many namespaces there were multiple definitions asserted for the properties in each namespace. For instance, multiple declarations for "name" or "value". Basically, common properties were declared in each namespace.

[mateusdz]

After the ontology refactors, we have reduced the namespaces count to one (stix namespace). All common properties are collected in one file and reused in all STIX objects. However, there exist several properties (that are not common properties, but) many objects are using, e.g., "name" and "description."

[mateusdz]

In file.owl, the file object is defined together with its extensions. Here both the base class and the extensions have the same property name and values in two properties, "name" and "size." In this case, to avoid conflicts, I have defined these properties only once without the descriptions of the properties.

[rhohimer]

This is a duplicate of Issue #20 regarding deduplication of datatype properties.