As I was working on /etc/skel/.vimrc, I took the liberty to make this
config a little more readable.
I provided the long forms of the mentioned settings plus a short
description - because it was done in /etc/vim/vimrc as well - and
integreated foldings.

A question though.
Some settings are done twice. First in /etc/vim/vimrc and again in
/etc/skel/.vimrc. Is that intended for e.g. user who just get .vimrc
on another distribution?