refs #576, refs #588 improved finders and default selection

* IATA code for airlines
* selection for airline designator returns list not single object
* misc finder functions for airline list
* formatting, use MS override Doxygen style

src/blackcore/icaodatareader.cpp

@@ -90,7 +90,7 @@ namespace BlackCore
         return m_countries.findBestMatchByCountryName(name);
     }
 
-    CAirlineIcaoCode CIcaoDataReader::getAirlineIcaoCodeForDesignator(const QString &designator) const
+    CAirlineIcaoCodeList CIcaoDataReader::getAirlineIcaoCodesForDesignator(const QString &designator) const
     {
         return getAirlineIcaoCodes().findByVDesignator(designator);
     }