Freebase topic search fixes

- In the server-side topic lookup, use correct
  URIs for the new Google-hosted Freebase API and
  alter the parsing to properly interpret the
  responses. This fixes the mouseover bug that
  occurred with the Freebase icon for a topic.

- In the browser-side topic creation screen, use
  the new Freebase Suggest widget. This allows the
  "disambiguation" auto-suggest text box to start
  working again.

- As part of the browser fix, update the jQuery
  used by the admin interface from 1.4.3 to 1.4.4.
  This is the minimum version required by the 
  Freebase Suggest widget.

- To avoid constraints on both kinds of requests
  (server and browser) use a Google "browser" API
  key when sending requests.