Fixes #213 - Validate STOCK_CHECK clause in shopping_cart page's header_php.php file
Refactor to fewer db queries and use different function, and reduce code duplication
Merge pull request #214 from drbyte/refactor_zen_stock_check

Fixes #213 - Validate STOCK_CHECK clause in shopping_cart page's header_php.php file
Merge pull request #99 from zencart/v160

zc 160