Increased size of unique identifier of objects: using uint64 instead of

int. Deep change in all concerned objects (Node, Source, Shader, etc.).
No behavior change, just more robust in duration.

View.h

@@ -85,7 +85,7 @@ protected:
     virtual void saveSettings();
 
     std::string current_action_;
-    int current_id_;
+    uint64_t current_id_;
     Mode mode_;
 };