Search Behaviors

Do not clear background until search is committed.
Do not do anything until search is committed.

In reference to Issue #67
iPhone recent search implementation.

In reference to issue #67
Changed MITNewsRecentSearchController from a ViewController to a TableViewController
Wrapping the search recent popover in a navigation controller to make the Clear button appear on the iPad.
Added Recents title and clear button to navigation bar.
added additional newline after closing brace.
Merge pull request #317 from MIT-Mobile/3.6/news-search

Adding recent search to iPhone and fixing search behaviors