task # 326 : Add a numbering module to suggest automatically a product ref

ChangeLog

htdocs/core/modules/product/mod_codeproduct_elephant.php

htdocs/core/modules/product/mod_codeproduct_leopard.php

htdocs/core/modules/product/modules_product.class.php

htdocs/install/mysql/data/llx_const.sql

htdocs/langs/fr_FR/admin.lang

htdocs/langs/fr_FR/companies.lang

htdocs/langs/fr_FR/products.lang

htdocs/product/admin/product.php

htdocs/product/fiche.php