Remove permalink structure update, as it has been deprecated.
Add new 'wpsc_display_products_page' action for other plugins to do things conditionally based on display type.  Important for Gold Cart to handle grid view enqueuing.
When there are no products in a category being displayed by a shortcode, we get undefined errors due to ->post being null.  This resolves that.
Merge remote-tracking branch 'upstream/master' into pr-1186-save-region-id-not-state-name