Add an olcs.getOlMap() getter

Author: gberaudo

src/ol3cesium.js

@@ -178,6 +178,15 @@ olcs.OLCesium.prototype.getCamera = function() {
 };
 
 
+/**
+ * @return {!ol.Map}
+ * @api
+ */
+olcs.OLCesium.prototype.getOlMap = function() {
+  return this.map_;
+};
+
+
 /**
  * @return {!Cesium.Scene}
  * @api