Improve determining atom priority when calculating chirality

[drroe]

V7.4.0.

This is mostly an under-the-hood change; provides a more strict adherence to Cahn-Ingold-Prelog rules for determining priority. This code is used in atom mapping and sugar building, so those commands should be a little more robust now.

Also finally enables the checkchirality byatom keyword. If byatom is specified, the chirality ('S' or 'R') for each atom selected by the atom mask will be determined if possible; otherwise 'Unknown' will be printed.

For example, to check the chirality of CA atoms in residues 1 to 8 in a system:

parm ../DPDP.parm7
trajin ../DPDP.nc
checkchirality DPDP out dpdp.byatom.dat byatom :1-8@CA

Output will look like:

#Frame   :2@CA :3@CA :4@CA :5@CA :6@CA :7@CA   :8@CA
       1     S     S     S     S     S     R Unknown
       2     S     S     S     S     S     R Unknown

Adds a test, updates the manual.

This also adds a missing file to the static library builds which should fix ambpdb.