[plt-scheme] Stopping MzTake

The documentation now adds:

> If you have just downloaded MzTake and are coming directly
> to the demos, know that once started, you can easily end
> execution of a debugger scipt by typing "(kill p)" into the
> Interactions window (freeing up resources). You can also pause
> a script with "(pause p)", and resume it with with "(start/resume p)",
> where P is any MzTake process.  In the "highway" demo, P is
> "radar-program", and P is "p" (meaning "process") for the others.

Two new .plt files are now available from

  http://www.cs.brown.edu/research/plt/software/mztake/

Shriram