refs #568, specialized model class for models from DB

* support for keys
* renamed to listmodeldbobjects (unified with views)
* key type as template parameter
* adjusted derived classes

src/blackgui/models/countrylistmodel.cpp

@@ -18,7 +18,7 @@ namespace BlackGui
     namespace Models
     {
         CCountryListModel::CCountryListModel(QObject *parent) :
-            CListModelBase("CountryListModel", parent)
+            CListModelDbObjects("CountryListModel", parent)
         {
             CColumn col("country", CCountry::IndexIcon);
             col.setSortPropertyIndex(CCountry::IndexIsoCode);