* Adds Atom atom map and rlabel apis
* Moves RLabels to their own namespace, adds other properties.
* Removes namespaces, liberally adds Atom to function names.
* move detail::computedPropName to RDKit::detail::computedPropName
o rdkit gains a RDKit::common_properties namespace that contains common string value properties
o Dict.h and below gain getPropIfPresent that attempts to retrieve a property and returns
true/false on success or failure. This is used to optimize access.
o rdkit learns how to pass property keys by reference, not value.
A new namespace has been added to RDKit, common_properties
that contains the std::string values for commonly used
properties. This helps to avoid typos in string values
but also avoids a creation of std::strings from character
values. All accessors (has/get/clear and getPropIfPresent) now pass
the key by reference.
Additionally, getPropIfPresent removes the double lookup
of hasProp/getProp which can be a significant speedup
in the smiles and smarts parsers (10-20%)
exceptions into python when reading a bad molecule. (Feature
request 1932875)
Modify constructors for both suppliers and parsers so that
throw BadFileExceptions if they cannot open the file. (Feature
request 1938303)
