Fixed menu bar for non-bundled OS X applications.

The menu bar for non-bundled applications did not become visible until
it had lost and regained focus.  This is fixed (somehow) by letting the
NSApplication run loop start and stop.

Technique by scoopr.

src/cocoa_platform.h

@@ -72,7 +72,6 @@ typedef struct _GLFWwindowNS
 typedef struct _GLFWlibraryNS
 {
     CGEventSourceRef eventSource;
-    id              delegate;
     id              autoreleasePool;
     id              cursor;