Open Radar

 
Summary:
By default, every NSMenu instance includes a 3-4 px padding on both top and bottom edges.

The fact isn't even noticed until you set a custom `view` property for the first or the last menu item. In that case you'll see a tiny whitespace just above the first menu item's view and below the last menu item's view (which definitely ruin the desired appearance of the menu).

The request is to make it possible to turn this padding space off without using any private APIs.

Steps to Reproduce:
1. Create an NSMenu instance;
2. Create an NSMenuItem object with a custom view set to its `view` property;
3. Make this object the first item of the menu;
4. Show the menu;

Expected Results:
There isn't any whitespace above the first menu item's view.

Actual Results:
There *is* a whitespace.

Notes:
There's a private NSMenu method for this: `_setHasPadding:onEdge:`.