title: Layering two Canvas' on top of each other + click event
body: <p>I want to layer two Canvas' elements on top of each other.
  They are used for a game, where the lower Canvas will display a hexgrid while the upper Canvas is meant to display issues/orders (basicly arrows or hex-highlighting - i dont want to redraw a massive hexgrid a zillion times) given by the player.</p>
  
  <p>The Canvas's are layered by zIndex 1/2.</p>
  
  <p>However, the problem is: The orders which are displayed on the top Canvas are supposed to be drawn in response to "click" and "mousemove" events to the bottom Canvas.</p>
  
  <p>Obviously, by layering the "orders" Canvas on top of the "hexgrid" canvas, any mousemove and click events will not be triggered by the "hexgrid" canvas anymore, since it doesnt receive the events anymore.</p>
  
  <p>Is there a way to "forward", i.e. propagate events from one element to another element or what would be another smart way to solve my problem ?</p>