Improve mouse click behavior of Aurorae Menu button

The general idea is: single click opens menu, double click closes
the window. The problem is that the when the menu is opened after
the single click, the menu will eat the second click. So double
click will not work.

This commit brings back the workaround from Aurorae2. The clicked
event is not used at all, but we start a timer on the press event
with the doubleClickInterval. If no double click appears during the
interval we open the menu, if there is a double click we close the
window.

The downside of this approach is that there is a slight delay between
clicking the menu button and the menu appearing. For that the right
click behavior is unchanged. That is right clicking opens the menu
instantly and double click to close it, is broken.