OEEnumerateTautomers was removing stereochemistry from all atoms that did not have
a valence of 4. This has been fixed so that other types of atoms with legitimate stereochemistry,
such as nitrogen and hypervalent atoms, no longer lose their stereochemistry information.
OEEnumerateFormalCharges has been fixed to properly handle 3D input. Previously, 3D
input would cause an incorrect number of hydrogen atoms and an incorrect valence state on adjusted heavy atoms.