[trunk] R5373 Menus all active on startup without score loaded

Typically when the trunk is loaded and no previous score was open, most of the menus were not active. Lately, most of the time when MS is opened, all the menus are active and available. "Continue Last Session" is selected under Prefs.

The debug window shows the following message "QFSFileEngine::open: No file name specified", but no other dialog comes up so it appears MS thinks is needs to open a previous file.