Return true if the right mouse button has been released on the current frame, and otherwise returns false.
A click differs from being down by only being recorded for one frame, rather then permanently, whilst the button is pressed.
Optionally, you can attach a block onto 'isRightClick' which is executed if the right mouse button is currently being clicked. The X and Y location of the mouse is passed in, to allow you to use it.
getControls().isRightClick() do |x, y|
// executed if right button is clicked