Nomenclature: fix search by name

The problem is that the initialized of NomenclatureItem are always set
to true in the constructor, but they should be only set once we have
computed the position.

For the moment I add some position length tests, but that is not very
clean.

src/core/modules/NomenclatureMgr.cpp

@@ -462,8 +462,10 @@ StelObjectP NomenclatureMgr::searchByName(const QString& englishName) const
 	{
 		foreach(const NomenclatureItemP& nItem, nomenclatureItems)
 		{
-			if (nItem->getNomenclatureType()!=NomenclatureItem::niSatelliteFeature && nItem->getEnglishName().toUpper() == englishName.toUpper())
+			if (nItem->initialized && nItem->XYZ.lengthSquared() > 0 && nItem->getNomenclatureType()!=NomenclatureItem::niSatelliteFeature && nItem->getEnglishName().toUpper() == englishName.toUpper())
+			{
 				return qSharedPointerCast<StelObject>(nItem);
+			}
 		}
 	}
 
@@ -476,8 +478,10 @@ StelObjectP NomenclatureMgr::searchByNameI18n(const QString& nameI18n) const
 	{
 		foreach(const NomenclatureItemP& nItem, nomenclatureItems)
 		{
-			if (nItem->getNomenclatureType()!=NomenclatureItem::niSatelliteFeature && nItem->getNameI18n().toUpper() == nameI18n.toUpper())
+			if (nItem->initialized && nItem->XYZ.lengthSquared() > 0 && nItem->getNomenclatureType()!=NomenclatureItem::niSatelliteFeature && nItem->getNameI18n().toUpper() == nameI18n.toUpper())
+			{
 				return qSharedPointerCast<StelObject>(nItem);
+			}
 		}
 	}