strip chart: thanks for you help

I finished my strip chart widget thanks to help from Tony S Yu, Benjamin
Root and others here. It supports multiple subplots and multiple
lines/subplot. Here's a copy if anyone is interested:
I plan to add it to the RO python package once I have tested it a bit
more. Meanwhile, the example code at the end uses a prerelease RO module
that I've also uploaded:

It uses the TkAgg back end, but is easily ported (as usual, event timing
is the main issue; I wish Python had its own event model that all GUIs
could use).

I think I finally got the animation API figured out well enough to
produce a robust result. Strip charts are intrinsically poor candidates
for the animation API because the time axis is constantly shifting, but
nonetheless animation does produce a small reduction in CPU usage.

Any feedback would be most welcome.


-- Russell