function move_mouse(x, y) {
        guac_touchscreen.currentState.fromClientPosition(element, x, y);
        if (guac_touchscreen.onmousemove)
            guac_touchscreen.onmousemove(guac_touchscreen.currentState);
    }
Moves the mouse to the given coordinates. These coordinates must be
relative to the browser window, as they will be translated based on
the touch event target's location within the browser window.

@private
@param {Number} x The X coordinate of the mouse pointer.
@param {Number} y The Y coordinate of the mouse pointer.