MFbed: Update the German documentation set.

doc/de_DE.ISO8859-1/books/handbook/l10n/chapter.sgml 1.121 -> 1.122
doc/de_DE.ISO8859-1/books/handbook/mirrors/chapter.sgml 1.425 -> 1.427
doc/de_DE.ISO8859-1/books/handbook/multimedia/chapter.sgml 1.121 -> 1.122
doc/de_DE.ISO8859-1/books/handbook/ports/chapter.sgml 1.260 -> 1.263 + fixes
doc/de_DE.ISO8859-1/books/handbook/users/chapter.sgml 1.55 -> 1.57

Obtained from: The FreeBSD German Documentation Project.