* Fixes#2437
getting the canonical atom ranking no longer results in molecules have a
RingInfo structure that's been initialized but contains nothing.
* update expected results for the MMPA tests
* not quite done yet
* Fixes#2244
* Fixes#2148
This fixes a few of the knock-on effects of the actual fix.
* Test that we still write SMILES properly
* Fixes#2266 (#2269)
* Fixes#2268 (#2270)
* Improve interactivity of output SVG (#2253)
* Add clickable atoms when tagAtoms() is called
* add python tests
* add class tags for atoms and bonds
* add marker to allow easy insertion of extra text
* Modify removeHs so that it does not remove degree 0 atoms
Update the docs at the same time.
* include a warning when not removing some Hs
* clear up a problem with the warning log