first slog through plotModel vignette

[beanumber]

What is the best way to do this? Should I wait until I'm finished to send the pull request? Does this look reasonable for a vignette?

[rpruim]

I think I'll do a fetch and then play the changes along the beta branch. Except for the smallest bug fixes, I don't generally work in the master branch. I typically work in branches off of the beta branch. Merge with beta when things are reasonably stable, and merge with master for "releases". github releases can be more frequent than CRAN releases. (You will see that the beta branch already has the 9000 extension to the version.)

[rpruim]

I like it as a start. I suggest we use trellis.par.set(theme = col.mosaic()) rather than the lattice default palette, and it would be good to choose examples that clearly show things like non-parallel lines and non-linear fits.

One note about how plotModel() works, ... is passed to xyplot() not to panel.xyplot(). (Of course, much of this is then passed on to panel.xyplot() by xyplot(). But it is better to think of these as arguments to xyplot().