Allow automorphic_rmsd to do comparisons between different name3s
Previously, automorphic_rmsd was written such that it assumed that the two
residues were of the same type -- or at least "close enough". This meant that
it checked the name3 for compatibility. This change opens things up such that
you can do automorphic_rmsd between two different name3s, as long as they're
equivalent in structure.
A complication is that HIS has to be special cased, as the "naive" matching
(atom types and bonding pattern match) means that HIS and HIS_D tautomers don't
qualify for automorphisms anymore.
* No test changes observed, except for things that are failing on the test server.