Merge pull request #4831 from RosettaCommons/jonpliu-patch-4
Carbohydates: adding glycolylated amino sugars to the database
This merge will add glycolylated amino sugars to the database.
A glycolyl group is an acetyl group with a hydroxyl group on its alpha carbon.
Sialic acids in other creatures besides humans sometimes have glycolyl groups instead of acetyl groups on the neuraminic acids.
Appropriate nomenclature will be added in PR #4793.