Partially working namelist .nl file dumping for debugging ROMs in FCEUX. It's incomplete because it doesn't export fully qualified names for labels/variables/constants (yet), it just exports the identifier for labels/variables, and the partially qualified attribute for constants. In the future, it'll handle this, but I need to improve the definition/environments symbol classes to be able to retrieve a qualifed name for each definition. And it needs to work even for anonymous packages.