Cloud storage: better window title

This makes it clear that we are working with the cloud storage and removes
the (in that case, redundant) branch name from the title.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/mainwindow.h

@@ -195,6 +195,7 @@ private:
 	CurrentState state;
 	QString filter();
 	static MainWindow *m_Instance;
+	QString displayedFilename(QString fullFilename);
 	bool askSaveChanges();
 	bool okToClose(QString message);
 	void closeCurrentFile();