Fix: mutualize code, more simple

dev/skeletons/skeleton_page.php

htdocs/comm/propal.php

htdocs/comm/propal/class/propal.class.php

htdocs/comm/propal/tpl/linkedobjectblock.tpl.php

htdocs/commande/fiche.php

htdocs/commande/liste.php

htdocs/commande/tpl/linkedobjectblock.tpl.php

htdocs/compta/facture.php

htdocs/compta/facture/class/facture.class.php

htdocs/compta/facture/tpl/linkedobjectblock.tpl.php

htdocs/compta/journal/index.php

htdocs/compta/propal.php

htdocs/contrat/fiche.php

htdocs/contrat/tpl/linkedobjectblock.tpl.php

htdocs/core/class/commonobject.class.php

htdocs/expedition/fiche.php

htdocs/expedition/shipment.php

htdocs/fourn/commande/fiche.php

htdocs/fourn/facture/fiche.php

htdocs/includes/modules/facture/doc/pdf_crabe.modules.php