Qual: Uniformize code and remove useless function

htdocs/admin/facture.php

htdocs/admin/societe.php

htdocs/compta/export/ComptaJournalPdf.class.php

htdocs/compta/paiement/cheque/remisecheque.class.php

htdocs/compta/paiement/rapport.php

htdocs/facture.class.php

...s/modules/expedition/pdf/pdf_expedition_merou.modules.php

.../modules/expedition/pdf/pdf_expedition_rouget.modules.php

htdocs/langs/en_US/admin.lang

htdocs/langs/fr_FR/admin.lang