Additional unit test of CID 42475007 stereoisomer.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
If the central atom is found in the ligand list replace it with an implicit hydrogen.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Removes the safety checked for implicit tetrahedral neighbours.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Can also now apply basic CIP rules to sulfinyl.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>