Remove runTime from OpenSpaceEngine and place in WindowWrapper instead

include/openspace/engine/openspaceengine.h

@@ -79,9 +79,6 @@ public:
     static OpenSpaceEngine& ref();
     static bool isCreated();
 
-    double runTime();
-    void setRunTime(double t);
-
     // callbacks
     void initialize();
     void initializeGL();
@@ -234,8 +231,6 @@ private:
         std::vector<std::function<bool (double, double)>> mouseScrollWheel;
     } _moduleCallbacks;
     
-    double _runTime;
-
     // Structure that is responsible for the delayed shutdown of the application
     struct {
         // Whether the application is currently in shutdown mode (i.e. counting down the

include/openspace/engine/wrapper/sgctwindowwrapper.h

@@ -49,6 +49,7 @@ public:
 
     double averageDeltaTime() const override;
     double deltaTime() const override;
+    double applicationTime() const override;
     glm::vec2 mousePosition() const override;
     uint32_t mouseButtons(int maxNumber) const override;
     glm::ivec2 currentWindowSize() const override;

include/openspace/engine/wrapper/windowwrapper.h

@@ -106,6 +106,13 @@ public:
     */
     virtual double deltaTime() const;
 
+    /**
+     * Returns the time that has passed (in seconds) since application start
+     * \return The time that has passed (in seconds) since application start
+     * @return [description]
+     */
+    virtual double applicationTime() const;
+
     /**
      * Returns the location of the mouse cursor in pixel screen coordinates. On default,
      * this method returns <code>0,0</code>.