If I click an icon to open up a window. Like the ships icon for example. Clicking it again should close it. Makes for a better UI experience and keeps the user from having to search for the X button(which btw is not in the standard upper left corner).
 "Castle Clicker : Builder Tycoon"){kind=icon}
 "Idle RPG"){kind=icon}
 "RPG Market Idle"){kind=icon}