2010-07-17: - Added French translation.
            - Listing of sets improved.
            - Dutch translation added and English labels improved.
            My thanks go to the friendly people who sent their patches and
            comments to me.
2009-03-01: Bug solved that occured when the first two letters of an element
            of a set were identical.
2006-01-09: Implementation of \listset changed. It now works within an \edef,
            but the element \empty is no longer allowed in a set.
2005-08-13: Documentation: Reference to LPPL added.
