In the branch `filtered` I am excluding those whose quantities
are zero but sup is nonzero.  I'm sure there's a clever way to flag
a value as coming from sup, but I would need to ensure that every
value for every year from every country was *just* sup.  A bit messy.

Note also that I'm failing reproducability in a big way here.  I
replaced the origninal csv -> hdf5 store with the reformatted version
from this file.  Those lines have been commented out.  Sorry.
Ready to run.
Updated docs for publishing.  Reverted some changes, which should
help with reproducability.
BUG: Calling bool on dataframe is bad.
Updated .gitignore for LaTeX files.
More content for writeup and starting to work on summary statistics.
Moved descritption and processing to the bottom.
New ignores, summaries, and cleanup.