FEATURE: 2013.5 - Added support for 9 digit zip codes when using the TaxCloud service for tax calculation.

Added support for 9 digit zip codes when using the TaxCloud service for tax calculation.

When using the TaxCloud 3rd party tax service (as of AmeriCommerce version 2013.5), the system will automatically use their address verification service to obtain the full 9 digit zip code for US addresses and will use this when calculating tax for maximum accuracy. Warehouses also now have a field to store the "plus 4" portion of their zip code which will be passed to TaxCloud as well when present.