Complete work on dol_banner on contracts

htdocs/contrat/card.php

htdocs/contrat/class/contrat.class.php

htdocs/core/class/commonobject.class.php

htdocs/core/class/html.form.class.php

htdocs/core/lib/functions.lib.php

htdocs/core/tpl/objectline_create.tpl.php

htdocs/install/mysql/migration/4.0.0-5.0.0.sql

htdocs/install/mysql/tables/llx_contrat.sql

htdocs/langs/en_US/admin.lang

htdocs/projet/card.php