Secrets file added.
Added implementation for API secrets.
Added a header for Macros.
Adds a login view and ways to switch login and main view rootViewControllers at the delegate.
Adds a singleton TwitterClient for Twitter API.
Authorization support added to client and root view switching based on auth state.
Connect to Twitter button connected with Client:authorize.
Merge branch 'master' of https://github.com/alexnj/iOSTwitter