Fix several security holes on api when used by external users

htdocs/comm/action/class/api_agendaevents.class.php

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

htdocs/commande/class/api_deprecated_commande.class.php

htdocs/commande/class/api_orders.class.php

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

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

htdocs/expensereport/class/api_expensereports.class.php

htdocs/fourn/class/api_supplier_invoices.class.php

htdocs/projet/class/api_projects.class.php

htdocs/projet/class/api_tasks.class.php

htdocs/societe/class/api_contacts.class.php

htdocs/societe/class/api_deprecated_thirdparty.class.php

htdocs/societe/class/api_thirdparties.class.php