Fix: _ not allowed into prestashop tags.
Fix: file with a specific mask not found
Fix: file with a specific mask not found, again
Generalize fix: file with a specific mask not found, again

Conflicts:
	htdocs/comm/propal.php
	htdocs/commande/fiche.php
	htdocs/compta/facture.php
	htdocs/expedition/fiche.php
	htdocs/fichinter/fiche.php
Merge remote-tracking branch 'origin/3.3' into develop

Conflicts:
	htdocs/comm/propal.php
	htdocs/core/lib/files.lib.php