[MOAB-dev] Getting ent set data when tag_size > 1

[James Porter]

While we're on this subject, we should probably think about adding
entity sets as a data type for tags. For MOAB, it doesn't matter since
the underlying type is the same, but requiring people to put sets in
entity-handle tags isn't consistent with the rest of iMesh, which has
separate functions for ents and sets.

For a more practical reason: entities and sets aren't convertible
between each other in PyTAPS (and I'd like to keep it that way if
possible). Without having a specific "set" data type for tags, I have to
either disallow setting tag data with entity set handles, or add in a
bunch of extra bookkeeping (which would get lost between Python sessions
anyway).

- Jim