Update CDK version from 2.12 to 2.13 in README
Align BEAM / CDK APIs.
Change the IChemObjectReader.Mode from two to three levels, Relaxed, Default, Strict.
This calculations should be on "visible" neighbours only. If we contract -NO2 for example we go from 3 equally spaced bonds to only 1 and the alignment here should trigger.
Fix a corner case in hydrogen suppression when a double bond has 2 hydrogens on the same end!
Fix the small cycle/ring algorithms and reuse them in the stereo element factory.
Fix a minor corner case in hydrogen normalisation.
Watch out for NaN when the offset of double bonds is computed.