Pass lua source directly into event_init

luprex/cpp/core/drivenengine.hpp

@@ -144,7 +144,7 @@ public:
     // The init callback.  You may override this in a subclass.
     // This will be called once at program initialization.
     //
-    virtual void event_init(int argc, char *argv[]) {}
+    virtual void event_init(std::string_view srcpk, int argc, char *argv[]) {}
 
     // The update callback.  You may override this in a subclass.
     // This will be called whenever anything changes.