[sugar] lots of scrolling in activities-list

[Eben Eliason]

> Not knowing what new design will replace the current activity frame, I think
> that not having so many activities pre-installed would help in this problem.
> Just like ubuntu does, provide a minimal set of most important programs, in
> this case focusing on learning and education, and then let the user add more
> from the wiki.

I certainly think this is a good idea myself, regardless of how
scalable the interface for displaying the activities is.  I think that
choosing a core set of 10 or so activities which will provide really
rich functionality while keeping the number of entry points and the
learning curve low is a good approach.

In fact, from the standpoint of emphasizing the ability to obtain new
activities from elsewhere, which should be an integral part of the
system, limiting the default set to the basics makes sense.

- Eben