extend Dr Scheme

[Luc Goossens <Luc.Goossens@vub.ac.be>]

I have defined two macro's, some aux functions and a single global
variable to enable some simple tracing.

What do I have to do exactly to make this avaiable to my students
in Dr Scheme.
I have looked through the documentation but it seems that one has
to know about a lot of things (like signed units etc) in order to
understand the docu about teachpacks.

I would be very grateful if somebody could just send me the code I
have to add.

Thanks.

Luc Goossens
Vrije Universiteit Brussel