Fix: Fix a lot of broken features when renaming produit to product

htdocs/comm/addpropal.php

htdocs/comm/propal.php

htdocs/commande/fiche.php

htdocs/compta/facture.php

htdocs/contrat/fiche.php

htdocs/core/class/conf.class.php

htdocs/core/photos_resize.php

htdocs/document.php

htdocs/fourn/product/fourn.php

htdocs/fourn/product/photos.php

htdocs/lib/images.lib.php

htdocs/main.inc.php

htdocs/product/canvas/default/product.default.class.php

htdocs/product/class/product.class.php

htdocs/product/document.php

htdocs/product/fiche.php

htdocs/product/photos.php

htdocs/product/price.php

htdocs/product/stats/fiche.php

htdocs/viewimage.php