Add grouping tests

I started this batch before seeing prior/new contributions, and so hope very much that this round of tests does not step on anyone's toes. With these, though, perhaps this portion of the CR becomes fully covered. Please let me know if I missed anything, or any other ways I could/should improve this batch of tests.
Fix blockquote tests

Thank you, Ms2ger, for the catch!

Does anything else need to be done to this batch, or was that it?
Merge pull request #21 from dzenana-trenutak/submission/dzenana.t-grouping

Add grouping tests