ChemicalDrift data tables

[manuelaghito]

think we should move the data in

def emission_factors(self, scrubber_type, chemical_compound):

def init_chemical_compound(self, chemical_compound = None):

out in a separate file, do you agree? what is the recommended format / way

[gauteh]

We use JSON for extra oils, would that work?

Maybe you can re-use the dir-js or xz-compressed db code for openoil.