AFMotion isn't needed since Bubblewrap gives us the same HTTP functionality.
Since the search screen already has a nav bar, we don't need to specify it again.

ProMotion ignores this value if the new screen being pushed onto the stack is already inside a UINavigationController.
Init the results table with a "loading" cell.
Make the search yelp method have a more relevant name.
Yelp API helper method.
Implement yelp api helper method in our screen.
Pass location and category to the homescreen as attributes instead of using the NSUserDefaults.
Implement refreshable on the results table.
Merge pull request #1 from markrickert/master

Some cleanup and separation of network code