Move printGpsCoords from MainTab to QtHelper

Last time I touched this I got a scream from dirk, but then I
looked at the code again and the problem that I faced was that
I broke translations in a sad way, well, now I broke it again.

However, this method shouldn't belong to MainTab ( because of
that thingy that I said before and also many others: Separate
the logic of your application from the UI specific code )

This generates a string that's going to be used on the Interface,
it doesn't display it on the interface. Move it down below makes
it easier to test ( I don't need to create an Widget and worry
about the parent-relationship with the mainwindow just to test
this function, for instance. )

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/maintab.h

@@ -120,7 +120,6 @@ private:
 	Completers completers;
 	void resetPallete();
 	void saveTags();
-	QString printGPSCoords(int lat, int lon);
 	void updateGpsCoordinates(const struct dive *dive);
 };