New: A generic order numbering module (depreciate all others)

htdocs/admin/commande.php

htdocs/admin/facture.php

htdocs/admin/propale.php

htdocs/includes/modules/commande/mod_commande_marbre.php

htdocs/includes/modules/commande/mod_commande_saphir.php

htdocs/includes/modules/facture/mercure/mercure.modules.php

htdocs/includes/modules/propale/mod_propale_saphir.php

htdocs/langs/en_US/admin.lang

htdocs/langs/en_US/bills.lang

htdocs/langs/fr_FR/admin.lang

htdocs/langs/fr_FR/bills.lang