Foursquare Search API with fallback

Switched to using the _search_ API - in my testing, the results were significantly more accurate than the _suggestCompletion_ API.  Also allows for some improvements for local accuracy - as the user types, it initially searches within 50 miles but if no results are found, it does a global check to find matches.  Also added some markup around the results list to add venue data to links.

Some of this might be specific to the app I'm integrating it with but I thought the improvements might useful to others as well.  Thanks a ton for the core.