Adds a UIViewController subclass, supAddMessageViewController. Sets the storyboard view controller to use this class instead of UIViewController.
Adds a UITableViewController subclass, SUPMessageListTableViewController. Sets the tableviewcontroller to use this class instead.
Adds unwindToList action to the SupMessagelistTableViewController
Links Cancel and Done buttons to the unwindToList: action
Adds a new SupMessage data class
Add a myMessages array to the MessageListTableViewController, loads the table view with dummy content in loadInitialData
Attaches a SUPMessage object created from textfield via prepareForSegue, adds to myMessages array in unwindToList