This is a modification of module "blockcategories" of Prestashop for configure de number of categories show in the front by default. The hidden categories can be visibles by clicking a "Show more" button.
More details: http://programwar.wordpress.com/2012/12/16/prestashop-permitir-configurar-el-numero-de-categorias-en-modulo-blockcategories/
IMPORTANT: The new configuration entries are not localized!!!