MFde: Update the German documentation set.

doc/de_DE.ISO8859-1/articles/new-users/article.sgml 1.48 -> 1.50
doc/de_DE.ISO8859-1/articles/version-guide/article.sgml 1.11 -> 1.13
doc/de_DE.ISO8859-1/books/handbook/book.sgml 1.174 -> 1.175
doc/de_DE.ISO8859-1/books/handbook/introduction/chapter.sgml 1.126 -> 1.132

Obtained from: The FreeBSD German Documentation Project