ecommerce 6.x-4.0-beta5

This is just a bug fix release which corrects some more core errors. Please test and let me know of any errors.

Changes since DRUPAL-6--4-0-BETA4:

• Fix API error in ec_receipt testing module
• #339827 - Remove additional serialize()
• #339847 - Make changes to allow the changing of the node item during
  hook_ec_checkout_validate_item()
• #330008 - Fixed issue where add to cart messages are sometimes wrong.
• Fix error on the checkout when there is no stored addresses.
• #340062 - fix missed rename of cart_current() to ec_cart_current()
• #341009 Fixed up the list of valid currencies to handle the utf8 file
• #288890 - This has been converted to ecommerce correctly
• #343188 - Fixed syntax error.
• #344441 - change reference to product.css to ec_product.css
• Change ec_available to use drupal_write_record() to save available info.
• #343194 - fix up validation call.
• Fix up issue with having no addresses.
• Fix up billing type filter to build the SQL correctly
• Fix up saving of stored addresses
• Remove the old method of loading transactions.
• #331401 - Fix issue where if a product doesn't have a quantity then it
  cannot be removed from the cart
• #347993 - Fix up return of json
• #330005 - Fix issue where checkout was not always calling ec_checkout_validate_item().
• #353496 add message to inform the system administrator to remove the
  product content type after uninstalling.
• #353601 Fix issue where the upgrade process is not working.
• #353225 Fix up issue of buynow now working when not using a link
• Remove email configurations which are now going to be handled by actions
  externally