Adds some tests that ensure some of the known problem cases work. In particular, it tests for some tricky stereo problems and shuffles the molecules around making sure they get the same hash.
It fixes a bug that existed with some tricky cage-like / bridge-head cases. In particular, this case:
Due to symmetry, setting explicit CIP designations on the atoms is not quite possible to do sequentially, but must be done in an explicit order. Alternatively (as is done in this pull request), designations can simply be set twice.
This does 3 things:
Due to symmetry, setting explicit CIP designations on the atoms is not quite possible to do sequentially, but must be done in an explicit order. Alternatively (as is done in this pull request), designations can simply be set twice.