Beginnings of network listener.

[ADDED]     OS X: Code to open a listening socket (WIP).
[ADDED]     OS X: Code to broadcast socket via Bonjour.

MasterPassword/Mac/MPAppDelegate.h

@@ -9,7 +9,7 @@
 #import <Cocoa/Cocoa.h>
 #import "MPPasswordWindowController.h"
 
-@interface MPAppDelegate : NSObject <NSApplicationDelegate>
+@interface MPAppDelegate : NSObject <NSApplicationDelegate, NSNetServiceDelegate>
 
 @property (assign) IBOutlet NSWindow                                    *window;
 
@@ -17,6 +17,8 @@
 @property (readonly, strong, nonatomic) NSManagedObjectModel            *managedObjectModel;
 @property (readonly, strong, nonatomic) NSManagedObjectContext          *managedObjectContext;
 
+@property (readonly, strong, nonatomic) NSNetService                    *netService;
+
 + (NSManagedObjectModel *)managedObjectModel;
 + (NSManagedObjectContext *)managedObjectContext;