QML UI: add feature to add current position when editing dive

This isn't quite perfect yet. If it takes too long to get the GPS fix (i.e., if
you save it before you get the fix), this will simply fail and not store a
position. But in normal conditions (you check the box, you edit the data, you
save), especially when outside on a dive boat, this should work fine.

For the other cases we need to implement some kind of callback to still collect
the data.

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

qt-mobile/qmlmanager.h

@@ -82,6 +82,7 @@ public slots:
 	void showMap(QString location);
 	QString getNumber(QString diveId);
 	QString getDate(QString diveId);
+	QString getCurrentPosition();
 
 private:
 	QString m_cloudUserName;