Clean language files

dev/translation/sanity_check_en_langfiles.php

htdocs/compta/bank/search.php

htdocs/core/lib/pdf.lib.php

...odules/mailings/thirdparties_services_expired.modules.php

htdocs/core/modules/modExpedition.class.php

htdocs/langs/en_US/accountancy.lang

htdocs/langs/en_US/banks.lang

htdocs/langs/en_US/bills.lang

htdocs/langs/en_US/categories.lang

htdocs/langs/en_US/companies.lang

htdocs/langs/en_US/errors.lang

htdocs/langs/en_US/exports.lang

htdocs/langs/en_US/help.lang

htdocs/langs/en_US/loan.lang

htdocs/langs/en_US/main.lang

htdocs/langs/en_US/margins.lang

htdocs/langs/en_US/multicurrency.lang

htdocs/langs/en_US/orders.lang

htdocs/langs/en_US/other.lang

htdocs/langs/en_US/products.lang