New: Ajout outil de dump par mysqldump

htdocs/admin/tools/dolibarr_export.php

htdocs/admin/tools/dolibarr_import.php

htdocs/admin/tools/export.php

htdocs/admin/tools/index.php

htdocs/admin/tools/pre.inc.php

htdocs/conf/conf.class.php

htdocs/document.php

htdocs/html.form.class.php

htdocs/includes/menus/barre_left/eldy_backoffice.php

htdocs/langs/en_US/admin.lang

htdocs/langs/fr_FR/admin.lang