MFbed: Minor update to the German documentation set.

doc/de_DE.ISO8859-1/books/handbook/multimedia/chapter.sgml 1.120 -> 1.121
doc/de_DE.ISO8859-1/books/handbook/x11/chapter.sgml 1.178 -> 1.179
doc/de_DE.ISO8859-1/share/sgml/mailing-lists.ent 1.55 -> 1.56

Obtained from: The FreeBSD German Documentation Project.