Update styling for "browse my ballot" page

This page allows the user to enter an address for candidates they would
like to browse. After entering a search. they will be sent to a new
page to see their results with further details. Which inputs are presented
to the user is controlled by the selection of one of the area buttons,
as decribed in issue #43

Also in this commit:

 - resized the navi_* icons in Inkscape.
 - some basic form validation is included (all the fields that are shown
   are considered required).
Style the browse my ballot results page

Added a new route and controller for the browse results. It uses the same
basic styling for the race selection as was used on the browse search page.
Not sure why the font size isn't getting inherited to all the children, so
it's duplicated in a number of spots.

The selected versions of the city, national, and state icons were missing,
so I edited the existing gray ones using the same color scheme as the
existing selected icons (per suggestion from ninjascience). This implements
most of issue #53.