API UIDropDownMenu AddButton

Adds a menu item to the currently open dropdown menu.
 UIDropDownMenu_AddButton(info, level)
== Arguments ==
; info : Table - a table describing the menu item to add. See the table below for recognized keys.
; level : Optional number - nesting level to which the menu item should be added. If 1, the menu item will be added to the outer-most menu level; 2 will add it to the first open sub-menu, 3 to the second open sub-menu, etc.
== Caveats ==
* Button tooltip doesn't work, if it doesn't have tooltipTitle filled.