Fixed a bug where OEAddColorAtoms would not
correctly add color atoms to a molecule that had the IntType field
on atoms filled from a previous calculation. IntType is scratch
space on atoms, so OEAddColorAtoms now clears
the IntType before adding color atoms to a molecule.
Changed one of the cation definitions in ImplicitMillsDean force field
from the too general (“n:1anaa1”) to the more specific (“n:1cncc1”).