v4.5.0

• chiangle and chiangles are added to calculate the sidechain dihedral angles in protein residues.
• mmCIF files with secondary structure annotations will now, by default, parse and assign secondary structure. Setting run_dssp or run_stride to true will cause DSSP or STRIDE to be run and provide the secondary structure, as before.
• A constructor for MetaGraph on a Chain is added that constructs a graph of atoms where edges are determined by the known bonds of standard amino acids in the chain.