MFbed: Update the German documentation set.

doc/de_DE.ISO8859-1/articles/contributing/article.sgml fixes only
doc/de_DE.ISO8859-1/books/faq/book.sgml 1.799 -> 1.802
doc/de_DE.ISO8859-1/books/handbook/desktop/chapter.sgml 1.72 -> 1.73
doc/de_DE.ISO8859-1/books/handbook/install/chapter.sgml 1.358 -> 1.360
doc/de_DE.ISO8859-1/books/handbook/l10n/chapter.sgml fixes only

Obtained from:  The FreeBSD German Documentation Project.