Relative line numbers (vim like)

[Anast Gramm]

Hello,

I was looking for a way to make linum mode like the relative numbers in
some vim videos I have seen, since it makes it very easy to do some stuff
really quick!

I found this (the first answer)
http://stackoverflow.com/questions/6874516/relative-line-numbers-in-emacs
and it pretty much works as expected, but I want one thing to change.
Instead of showing 0 at the current line I want to show the
actual line number.

I figured I could use what-line to get "Line %d" as a result
and then split it and the the 2nd half with the number and use this.

I don't know lisp, so I can't do this!

Any help would be appreciated!