Fixed notification for outline view to just subscribe to single instances not all notifications as we are now dealing with multiple windows.

MacPass/MPOutlineViewController.h

@@ -8,8 +8,12 @@
 
 #import "MPViewController.h"
 
+@class MPOutlineViewDelegate;
+
 @interface MPOutlineViewController : MPViewController
 
+@property (retain, readonly) MPOutlineViewDelegate *outlineDelegate;
+
 - (void)clearSelection;
 - (void)showOutline;