refs #720, improved distributor and airline/livery detection

* mark data read from DB (req. for string key where existing key value is not reliable indicator for DB data)
* detect distributors by part of model string
* use a simplified name (no spaces, no special characters) to find a match
* allow to obtain model strings (=keys) as set and list

src/blackmisc/simulation/distributor.h

@@ -130,6 +130,7 @@ namespace BlackMisc
             BLACK_METACLASS(
                 CDistributor,
                 BLACK_METAMEMBER(dbKey, 0, CaseInsensitiveComparison),
+                BLACK_METAMEMBER(loadedFromDb),
                 BLACK_METAMEMBER(timestampMSecsSinceEpoch),
                 BLACK_METAMEMBER(order),
                 BLACK_METAMEMBER(description),