adding to vignette.

build rules for vignette still wonky:
bibtex and rerun is unweildy.
make check runs the unit tests, which are slow, so vignette checking is
difficult.
OTOH, the 'staged_vignette' hack cannot (yet) find the bib files.
faster vignette building.

ready to start writing the vignette.
vignetteing.

makefile still wonky: how to make build w/out making the vignette, but insure
it goes in the package? I do not know.