Merge pull request #4457 from RosettaCommons/JWLabonte/PTMs/cofactors
Coenzymes: Adding SAM and S-adenosyl homocysteine to the database
This merge adds .params files for SAM and its demethylated version.
It also adds an integration test for the loading of cofactors in our list.
This merge also fixes a bug that caused the sugar_bb scoring term to crash when ligands were involved.