Add classification_functions.R
Add classification vignette.
Have a working version with suitable .tex file.

Consider moving into makefigs.
Add instructions for making table.
Update DESCRIPTION
feature.rm and avg.feature.rm now allow num.rm to be zero.

By setting num.rm to zero, we can test the effect of keeping all
features in the classifier.
move classification vignette
Write .tex file in current directory
Update TODO.org!