Issue : Cannot unfocus an element in the menu

[ghost]

While you press a combobox for example, anything in the menu is blocked, and it doesn't get other input (say I want to change a value from a slider).

I have to re-click on the same element to unfocus, then I can modify other elements.

We should be able to click on a dead zone in the menu, and it unfocus the element automatically.

[emilyinure]

Should be fixed