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/stringutils.h

@@ -78,6 +78,9 @@ namespace BlackMisc
     //! Case insensitive string compare
     BLACKMISC_EXPORT bool caseInsensitiveStringCompare(const QString &c1, const QString &c2);
 
+    //! Get a simplified upper case name for searching by removing all characters except A-Z
+    BLACKMISC_EXPORT QString simplifyNameForSearch(const QString &name);
+
     namespace Mixin
     {
         /*!