Re-add bounty filter controls to the index page. It appears they were never re-implemented when the filter controls were pulled into their own parital.
Complete the styling for the user dashboards.
The bounty filters are now available on any page that includes the controls' HTML.

This change Allows the controls to appear on any page that has a bounty
list. Previously the filters controls were hard-coded to only show up on
the Bounty#index page.
Update bounty filter Javascript to work again.

The bounty filtering was broken because it targeted the id of the
container for the bounty list. That id was changed to be the container's
class instead, breaking the bounty filtering. This change to the
filtering script targets the class instead of the id, so bounty
filtering works again.
Move the general filters partial from the layout folder into the shared folder.
Allow bounty filter controls to work on the bounty list displayed on the user dashboard.
Move the artist-specific filters partial to the shared folder.
Restore artist-specific bounty filters on the index page, which were removed at some point.