Verify grouping logic in count functions

[tavinathanson]

We've often run into trouble with different de-duping mechanisms prior to grouping variants, epitopes, etc. This should be better tested.

[arahuja]

Are there issues here to be aware of or is this just saying errors are possible?

[tavinathanson]

The latter; I didn't think too hard about the exact grouping mechanisms for each count, and I know different grouping/de-dup'ing strategies have gotten us into trouble before.