added garbage collection to obj mgr

include/lol/util/ObjectManager.hpp

@@ -56,6 +56,17 @@ namespace lol
 			return it->second;
 		}
 
+		inline void Return(unsigned int id)
+		{
+			auto it = objects.find(id);
+
+			if (it == objects.end())
+				return;
+
+			if (it->second.use_count() < 3)	// I hope I don't forget about this if I ever go multithreaded
+				objects.erase(it);
+		}
+
 	private:
 		ObjectManager() {}