Add handlebars for JS templating

There is a convenient gem 'handlebars_assets' which will put any
handlebars template in assets/js/templates/(filename).hbs into a global
JS variable `HandlebarsTemplates['(filename)']`. This *should* work with
asset precompilation as well.

The main reason is maintainability... the candidate template had
spiraled out of control in complexity and this seems a lot more
reasonable to me.

The only downside is that you have to be a lot more explicit with the
variables / context you pass into the rendering, which is kind of a
drag because it requires more logic in the Backbone view. But that seems
relatively nice to me, since that means the view itself is much simpler.
Handlebars for the contributors list
Make search not reload the page

Backbone FTW!
Merge pull request #281 from mikeubell/master

Move footnotes above candidates without data.
Update map.csv and document
Identify a few more unions.
Remove candidates self-contributions from the pie chart.
Merge pull request #280 from mikeubell/Map

Update map.csv and document
Merge pull request #277 from tdooner/handlebars

Add handlebars for JS templating
Make formatting more consistent between charts.
Merge pull request #286 from vbrown608/master

Make formatting more consistent between charts.
Add form 497.