Fix: New: Differentiate text and img for better accessibility.

htdocs/core/boxes/box_graph_invoices_permonth.php

htdocs/core/boxes/box_graph_invoices_supplier_permonth.php

htdocs/core/boxes/box_graph_orders_permonth.php

htdocs/core/boxes/box_graph_orders_supplier_permonth.php

htdocs/core/boxes/box_graph_product_distribution.php

htdocs/core/boxes/box_graph_propales_permonth.php

htdocs/core/boxes/modules_boxes.php

htdocs/core/lib/functions.lib.php

htdocs/holiday/admin/holiday.php

htdocs/main.inc.php