Added unit tests for daysToNearestBirthday method in Contact class. Added window and controller to handle OAuth token requests for LinkedIn and Twitter accounts. Added LinkedIn and Twitter-related options to the Preferences window. Updated build settings to Xcode 5 recommended values.
Added OAuth authentication for LinkedIn and Twitter accounts via OAuthConsumer API. Updated layout of WebView in OAuthLoginWindow.xib. Updated PreferencesWindow.xib to latest Interface Builder format.