Fixes: Polish submit message checking.

Details: Use a global model for nicknames that is shared by all dialogs to solve the updating  problems. Make p4 plugin submit work again. Force a submit prompt in case of shutdown or editor close (as opposed to user clickling on "Submit").

src/plugins/subversion/subversionplugin.h

@@ -168,6 +168,7 @@ private:
     QAction *m_submitDiffAction;
     QAction *m_submitUndoAction;
     QAction *m_submitRedoAction;
+    bool    m_submitActionTriggered;
 
     static const char * const SUBVERSION_MENU;
     static const char * const ADD;