Having the hydrogens present when reading the MDL Mol files means the canonicalisation now changes. One can confirm the SMILES are the same but only written differently. Two tests checked that ring closures could include double bond symbols 'C=1C=CC=CC=1'. This is no longer the case as the canonical form doesn't have the double bonds on the closures but the output is correct.

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