Adds IBOutlet to delegate properties

Summary: Makes delegates designable using interface builder.

Test Plan: Tried designing delegates using IB. Ran unit tests.

Reviewers: clang, ayden, mmarucheck

Reviewed By: mmarucheck

CC: msdkexp@

Differential Revision: https://phabricator.fb.com/D546635

Task ID: 1342888

src/FBLoginView.h

@@ -55,7 +55,7 @@
  @abstract
  The delegate object that receives updates for selection and display control.
  */
-@property (nonatomic, assign) id<FBLoginViewDelegate> delegate;
+@property (nonatomic, assign) IBOutlet id<FBLoginViewDelegate> delegate;
 
 @end
 

src/FBViewController.h

@@ -96,7 +96,7 @@ typedef void (^FBModalCompletionHandler)(FBViewController *sender, BOOL donePres
  The delegate that will be called when Cancel or Done is pressed. Derived classes may specify
  derived types for their delegates that provide additional functionality.
  */
-@property (nonatomic, assign) id<FBViewControllerDelegate> delegate;
+@property (nonatomic, assign) IBOutlet id<FBViewControllerDelegate> delegate;
 
 /*!
  @abstract