Content is from
   http://www.localeplanet.com

As of 16 May 2013, localeplanet supports date formatting and number
formatting, but not time formatting.  (Though it does have
translations for AM and PM.)  This should be enough for our purposes,
which include translating highcharts, the various date-pickers we
have, our own commafy method, etc.

We like localeplanet because the data files are very short, and
they're separated out per-language, just like we like.

The short `download.sh` script downloads the latest data from
localeplanet, making sure to get all the languages that babel (the python babel,
not the JS babel) supports. It assumes that this localeplant repo and the
webapp repo are up-to-date sibling folders.

After running `download.sh`, you also need to run `add_module_exports.py`. This
script updates each `icu.*.js` file to make it so that icu is exported as well
as attached to the window object. This makes it so that icu becomes available
when running our JS inside Node.

See [`add_module_exports.py`](./add_module_exports.py) for instructions and
details of the exact modifications it makes.