remove natbib.cfg, update generated files, add class option achemso, add class option woosterchicago, update username.tex

I added achemso and woosterchicago class options to woosterthesis.cls
lines 187-196, 1529-1545 and then added its use in username.tex lines
14-16, 255-259. Removed the natbib.cfg file since this was moved to the
class file.