Also fix IP of faui06.

For consistency with the other slides.

Niemand weiss, was PS-Dateien sind.

Students will probably don't recognize the old username
format (sivvnnnn) as valid.

So we call this course everywhere the same.

17ws is preferred because this will cause a
correct natural sorting of terms. It was also
used until 16ws and is used in other repositories.

rubber sometimes forgets dependencies on included files.

It was more confusing for most students than ncdu and requires X.