Merge pull request #497 from RosettaCommons/vmullig/gamma_aas
Adding gamma-amino acids to the properties list
Also:
- Tweaking some core code that was preventing mainchain torsions from being identified properly in C-aminomethylated terminal resiudes (resulting in changes to my backbonegridsampler integration test).
- Updating protein patches to work with gamma-amino acids.
- Adding GABA to the database (gamma-aminobutyric acid -- basically gamma-homoglycine).