Trim down unnecessarily long query strings

When submitting search forms, fields that aren't filled out will still
appear in the url, taking up space and making the url harder to
understand.

This commit removes blank parameters from the query string and redirects
to the new url. Since these blank parameters were already ignored by the
individual #search methods this shouldn't negatively affect anything.

app/controllers/application_controller.rb

@@ -103,6 +103,10 @@ protected
   def normalize_search
     if request.get?
       params[:search] ||= {}
+      changed = params[:search].reject! {|k,v| v.blank?}
+      unless changed.nil?
+        redirect_to params
+      end
     end
   end