Text filter is case-insensitive.
 - Non-UK products were not correctly ignored.
 - Some reeled products don't have 'reeling' attribute correctly set. Such products
 are detected from their 'displayName' attribute.
- Basket's total and items show zero if the basket is empty as oppose to an empty string.
- xmlsimple gem is not needed
Basket grid GUI updates are disabled when deleting all items to avoid any flickering.