[sugar] Pippy and Calculate

[Yoshiki Ohshima]

  Jameson,

  Thanks!  Having a simple plotter combined with Pippy would be a good
idea.  Even just making a character/console based plotter would give
kids a lot to learn, at the same time.

> The one place Calculator is clearly better than Pippy is as a nice simple Sugar example app, we can let it be nothing
> but that (not in the default build, but available and easily installable if anyone wants it).

  Probably.  But by looking at a serious performance issue and some
parsing problems, I thought some joint effort to make Pippy better
might be good for the community...

-- Yoshiki