MFde: Update the german documentation.

Update some chapters and resync others with the latest version.
The subchapters about "Portsnap: A Ports Collection Update Tool"
and "Updating the Documentation Set" in the cutting-egde chapter
were translated separately, that is why the "based on"-revision
counter was not increased.

/books/faq/book.sgml 1.1116 -> 1.1117
books/handbook/config/chapter.sgml 1.229 -> 1.238
books/handbook/disks/chapter.sgml 1.291 -> 1.292
books/handbook/firewalls/chapter.sgml 1.81 -> 1.83
books/handbook/kernelconfig/chapter.sgml 1.192 -> 1.193
books/handbook/l10n/chapter.sgml 1.128 -> 1.129
books/handbook/linuxemu/chapter.sgml 1.137 -> 1.139
books/handbook/multimedia/chapter.sgml 1.132 -> 1.135
books/handbook/network-servers/chapter.sgml 1.111 -> 1.116
books/handbook/virtualization/chapter.sgml 1.19 -> 1.20

Obtained from: The FreeBSD German Documentation Project
Approved by: jkois (mentor)