Qual: Amélioration messages a l'install

htdocs/admin/company.php

htdocs/install/default.css

htdocs/install/fileconf.php

htdocs/install/inc.php

htdocs/install/licence.php

htdocs/langs/en_US/install.lang

htdocs/langs/en_US/main.lang

htdocs/langs/en_US/users.lang

htdocs/langs/fr_FR/install.lang

htdocs/langs/fr_FR/main.lang

htdocs/langs/fr_FR/users.lang

htdocs/lib/functions.inc.php

htdocs/viewimage.php