[AC-2795] iOS: UI.iPhone - NavigationGroup.close() crashes with EXC_BAD_ACCESS

var root = Ti.UI.createWindow({
  title: 'Root Window',
  backgroundColor: 'white',
  layout: 'vertical',
});

var startButton = Ti.UI.createButton({
  title: 'Start Test',
  height:'50dp',
  width:'200dp',
  top:'20dp',  
});
startButton.addEventListener('click', function() {
  // for (;;) {
    var windows = [], n = Math.floor(Math.random() * 10) + 3;
    for (var i=0; i < n; i++) {
      var w = Ti.UI.createWindow({
        title: 'Window '+i,
        backgroundColor: 'white',
        layout: 'vertical',
      });
      windows.push(w);
      navgroup.open(w, {animated:false});
      Ti.API.info('opened '+w.title);
    }
    
    while (windows.length > 0) {
      var winToClose = windows.pop();
      navgroup.close(winToClose, { animated: false});
      Ti.API.info('closed '+w.title);
    }
  // }
});
root.add(startButton);

var navgroup = Ti.UI.iPhone.createNavigationGroup({
  window: root
});

var container = Ti.UI.createWindow();
container.add(navgroup);
container.open();

@@ -117,8 +119,9 @@
 	NSMutableArray* newControllers = [NSMutableArray arrayWithArray:controller.viewControllers];
 	BOOL animated = [TiUtils boolValue:@"animated" properties:properties def:(windowController == [newControllers lastObject])];
 	[newControllers removeObject:windowController];
-	[closingProxy autorelease];
-	closingProxy = [window retain];
+//	[closingProxy autorelease];
+//	closingProxy = [window retain];
+    [window close:nil];
 	[controller setViewControllers:newControllers animated:animated];
 	
 }
@@ -152,9 +155,9 @@
 		}
 		[self setVisibleProxy:newWindow];
 	}
-	[closingProxy close:nil];
-	[closingProxy release];
-	closingProxy = nil;
+//	[closingProxy close:nil];
+//	[closingProxy release];
+//	closingProxy = nil;
 	opening = NO;
 	[newWindow windowDidOpen];
 }