MFbed: Update the German website.
www/de/includes.sgml fixes only
www/de/includes.xsl fixes only
www/de/mailto.sgml 1.29 -> 1.30
www/de/send-pr.sgml 1.51 -> 1.52
www/de/where.sgml 1.79 -> 1.82
www/de/docs/books.sgml 1.14 -> 1.16
www/de/news/news.xml 1.372 -> 1.374
www/de/platforms/arm.sgml 1.5 -> 1.7
www/de/projects/newbies.sgml 1.49 -> 1.51
Obtained from: The FreeBSD German Documentation Project.