Refine visualization vertical bars

Display a vertical bar, even if there are no elections in that
year.  To implement this, update Elections.yearSummary() to return
objects with zero counts for years without elections.  Also cache
the result of Elections.years() as it will likely be called
multiple times.

Addresses https://github.com/openelections/openelections.github.io/issues/33
Evenly space visualization horizontal lines

Addresses https://github.com/openelections/openelections.github.io/issues/36
Add "in progress" status for results

Make in progress blue, raw green and clean pink.

Also clean up SASS file by removing trailing whitespace from lines
and converting comment syntax so comments won't show up in output.

Addresses https://github.com/openelections/openelections.github.io/issues/19
Separate lists of dev and metadata volunteers

Add volunteer names to table views.

Refactor volunteer name list generation into a model method.

Addresses
https://github.com/openelections/openelections.github.io/issues/22,
https://github.com/openelections/openelections.github.io/issues/32
Make state names link in status table

Make state name a link to the results detail page for that state.

Make links pink and bold.

Factor logic to generate link to the results detail page into a
model method.

Addresses
https://github.com/openelections/openelections.github.io/issues/32
Update shape scales to reflect spec

Update the scales used to determine the sizes of the shapes used
to represent the number of elections in a given year so that they
match the spec at
https://drive.google.com/file/d/0B0i_cKL1FSAfZ01mSlM5NHhsMTg/edit?usp=sharing

Instead of using a linear scale with the range between zero and
the maximum size (based on bar width), calculate the domain based
on the expected maximum number of elections and calculate the
range so that the sizes increase by a specified factor up to the
maximum.

Addresses
https://github.com/openelections/openelections.github.io/issues/35
Add election count legend

With the narrower vertical bars, the race type legend now fits,
so add it in.
Merge branch 'refine_visualization' into download_results