refs #568, specialized view class for DB objects

* CViewWithDbObjects
* new menu for views (delete key, remove)
* adjusted derived classes

src/blackgui/views/airlineicaoview.cpp

@@ -17,7 +17,7 @@ namespace BlackGui
 {
     namespace Views
     {
-        CAirlineIcaoCodeView::CAirlineIcaoCodeView(QWidget *parent) : CViewBase(parent)
+        CAirlineIcaoCodeView::CAirlineIcaoCodeView(QWidget *parent) : CViewWithDbObjects(parent)
         {
             this->m_menus |= MenuBackend;
             this->standardInit(new CAirlineIcaoCodeListModel(this));