Updated SELFHTML 8.1 Debian Package

SELFHTML is a very popular German (X)HTML reference and tutorial which also covers CSS, JavaScript and related technologies.
Today, I have updated the SELFHTML Debian package to the new upstream version 8.1 (I'm the Debian maintainer of the SELFHTML package).
It's probably too late for the upcoming sarge release, but at least the package is now available for those who use unstable (and testing, soon).