(svn r13024) -Codechange: do not use WE_MOUSELOOP when WE_TICK suffices, rename WE_4 to something more descriptive and correct some (completely incorrect) comments.

src/openttd.cpp

@@ -97,6 +97,7 @@ void MusicLoop();
 void ResetMusic();
 void ResetOldNames();
 void ProcessAsyncSaveFinish();
+void CallWindowTickEvent();
 
 extern void SetDifficultyLevel(int mode, GameOptions *gm_opt);
 extern Player* DoStartupNewPlayer(bool is_ai);