Merge pull request #709 from RosettaCommons/JWLabonte/sugars/loops
Patch System: adding new PatchOperation DELETE_VARIANT_TYPE
This merge allows one to remove a VariantType from a ResidueType, expanding all the fun things we can do with the patch system. I also needed it to make modified sialic acids, which are key to eukaryotic glycobiology.
also added a new integration test to the carbohydrates tests to demonstrate
carbohydrates test changes expected