Merge pull request #4069 from RosettaCommons/JWLabonte/PTMs/parsing
EnzymaticMovers: Adding parsing of nucleic acid sequences to the EnzymaticMover system
This merge allows the EnzymeManager to parse nucleic acid sequons, allowing for EnzymaticMovers that simulate such enzymes as DNA methyltransferases.
This merge will also add a VARIANT_OF record type for .params files such that one can specify the base ResidueType of a VariantType that is defined by a .params file instead of by a patch file, as is typical.
thanks to @everyday847 for teaching me the 1-letter NA code
thanks to @roccomoretti for the code review
All tests pass.