* Support Chemical Markup Language, CML, for writing
Implement RDKit::MolToCMLBlock and RDKit::MolToCMLFile
http://www.xml-cml.org/
* a number of cleanups and fixes
1. stop writing the cml: namespace to the output. Tools like marvin can't read that and it's not nececssary
2. fix the H count
3. continue writing atom info for 2D confs
4. simplify the writing of atom parity
* make the conformer optional
write bond hash/wedge information
* update the expected python results
* Remove overloaded function
Co-authored-by: greg landrum <greg.landrum@gmail.com>
