Instance vars and constants, remove threading.
Rename some methods, generate ZipPage class.
Give methods to ZipPage control.
Give ZipPage its own file.
Rename file, Harvester => ZipHarvester.
Refine design.
Extract address_queries, reorder, implement cos.
Leverage enumerable in ZipCodes.
Extend enumerable instead.
Refine, bug fix, and add niceties.
Moar logging.