A carbon cation with no pi bonds donates 0 electrons.
Allow option of stricter parsing - two utilise were provided for creating the parser.
Strict/Loose should return the graph not the parser.
Correct flag for loose parser.
Loose and strict parsing of 'bare' hydrogen and isotopes.
Strict parser doesn't allow 'abnormal' aromatic elements which aren't in the OpenSMILES specification
Parser now needs a flag to indicate if the parsing should be strict or loose.