Mulitparam querying works!

+ Querying works. It uses a regex to strip out blank URL params before querying, because blank URL params interfere with the query.
+ Added User, PCVProfile, and blog Entry fixtures to make data more standardized across our dev environments. I'll add more later, and feel free to add more yourselves. It's just JSON in `apps/pcvblog/fixtures/fixtures.json`. Load with `python manage.py loaddata fixtures.json`. In there now:
  + Home states: MA, OH
  + Sectors: Environment, Education
  + Countries of Service: UG (Uganda), NI (Nicaragua)
+ Added a cursory unstyled "Clear Search" button to reset the form and posts.