Molsystem

* the Crystallographic Open Database CIF files seems to use upper case X, Y, Z in
explicit symmetry operators. These need to be lowercased in the code.

* Fixed issue 72, where symmetry was not correctly handled for trigonal and
hexagonal cells where atoms had coordinates of 1/3 or 2/3.

* Reading CIF files could fail if the symmetry operators were given
* The symmetry handling did not recognize hexagonal spacegroups without :H. Changed
so if the hexagonal group name has neither :H or :R, the hexagonal setting is
assumed.
* When finding the spacegroup from the symmetry operators, hard-coded to the P1 case
to avoid what seems like a bug in spglib.
* Enhanced to use the full International Tables HM name for spacegroups, translating
the input to that standard name.

* Fixed bug with symmetry operators containing blanks, e.g. 'x, y, z' rather than
'x,y,z'
* Added handling of symmetry when get properties of atoms
* Added method to lower symmetry to P1/C1

2023.10.30 -- Support for InChI improved, RMSD and PubChem added...
* Adds support for aligning structures and calculating RMSD
* Adds support for working directly with PubChem to get structures, IUPAC names,
etc.
* Improves support for InChI, working around issues in both OpenBabel and RDKit.
* Added substantial new functionality for spacegroups and primitive cell handling,
but still not complete.

* Added getting the spacegroup from the symmetry operators
* Fixed updating the coordinates from the primitive cell

2023.9.5 -- Support for velocities of atoms.

2023.8.30 -- Support for spacegroup symmetry.

2023.8.27 -- Bugfix: writing SDF did not handle charge and multiplicity.

* Added ability to get lists of systems or configurations filtered by name
* Improved handling of properties on just a system, not configuration
* Added ability to filter properties retrieved
* Improved handling of properties when creating OpenBabel OB_MOL object