Undo: on save remove focus from active fields

The editing of a dive field is only performed when focus
is removed from the field. On pressing CTRL-s, the changes
in the currently active field were therefore not saved.
Remove the focus from all fields to trigger an edit command
yand thus ensure that all changes are saved.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

desktop-widgets/tab-widgets/maintab.h

@@ -53,6 +53,7 @@ public:
 	void updateCoordinatesText(qreal lat, qreal lon);
 	void refreshDisplayedDiveSite();
 	void nextInputField(QKeyEvent *event);
+	void stealFocus();
 
 signals:
 	void diveSiteChanged();