refs #768, update of value objects

* Adjusted validation
* Use default airline object when a color livery is created (refs #774 also)
* Added/improved completer strings (e.g. getVDesignatorDbKey())
* utility functions in lists

src/blackmisc/aviation/aircrafticaocodelist.h

@@ -94,6 +94,9 @@ namespace BlackMisc
             //! All ICAO codes, no duplicates
             QStringList allIcaoCodes(bool noUnspecified = true) const;
 
+            //! All manufacturers
+            QStringList allManufacturers(bool onlyKnownDesignators = true) const;
+
             //! From our database JSON format
             static CAircraftIcaoCodeList fromDatabaseJson(const QJsonArray &array, bool ignoreIncomplete = true);
         };