Hide Categories with category cache

for osCommerce Online Merchant v2.3

This is an osCommerce 2.3 version of the Activate or Inactivate Categories contribution. The main addition is the creation of a category cache file that reduces the need to read the database when obtaining category information which can speed web site display, particularly when displaying product counts on sites with a large number of products in deeply nested categories. This cache file is automatically updated as needed. Features: * Hide or show any category as desired. Subcategories of hidden categories are automatically hidden. * Choose whether or not to completely hide products that exist only in hidden categories. * Category cache file reduces the need to read from the database, thus speeding web site display. * Category cache file is automatically rebuilt any time category information is changed. * Category cache file is automatically rebuilt when showing product counts and a product is added, deleted or undergoes a status change.