Add getOpacity/setOpacity to canvaslayer

lib/torque/gmaps/CanvasLayer.js

@@ -287,6 +287,24 @@ CanvasLayer.prototype.setPaneName = function(paneName) {
   this.setPane_();
 };
 
+/**
+ * Set the opacity for the canvas.
+ * 
+ * @param {number} opacity The opacity of the canvas
+ * /
+CanvasLayer.prototype.setOpacity = function (opacity) {
+  this.canvas.style.opacity = opacity;
+};
+
+/**
+ * Get the canvases opacity.
+ * 
+ * @return {number} The opacity of the canvas
+ * /
+CanvasLayer.prototype.getOpacity = function () {
+  return this.canvas.style.opacity;
+};
+
 /**
  * @return {string} The name of the current container pane.
  */