MFbed: Update the German documentation set.

doc/de_DE.ISO8859-1/books/faq/book.sgml 1.790 -> 1.792
doc/de_DE.ISO8859-1/books/handbook/disks/chapter.sgml 1.270 -> 1.271
doc/de_DE.ISO8859-1/books/handbook/linuxemu/chapter.sgml 1.132 -> 1.133
doc/de_DE.ISO8859-1/books/handbook/mirrors/chapter.sgml 1.427 -> 1.428
doc/de_DE.ISO8859-1/books/handbook/multimedia/chapter.sgml 1.122 -> 1.126
doc/de_DE.ISO8859-1/books/handbook/vinum/chapter.sgml 1.42 -> 1.44

Obtained from: The FreeBSD German Documentation Project.