task #8618: improved supplier directory structure

htdocs/admin/fournisseur.php

htdocs/core/class/html.formfile.class.php

htdocs/fourn/class/fournisseur.commande.class.php

htdocs/fourn/commande/dispatch.php

htdocs/fourn/commande/fiche.php

...odules/supplier/order/mod_commande_fournisseur_muguet.php

...ules/supplier/order/mod_commande_fournisseur_orchidee.php

...es/modules/supplier/order/modules_commandefournisseur.php

.../includes/modules/supplier/order/pdf_muscadet.modules.php