Ref T185 Enable spline interpolation with only one position update,

by just copying it three times, so planes can be rendered without waiting for more updates.

src/blackmisc/aviation/aircraftpartslist.cpp

@@ -22,5 +22,9 @@ namespace BlackMisc
             CSequence<CAircraftParts>(other)
         { }
 
+        CAircraftPartsList::CAircraftPartsList(std::initializer_list<CAircraftParts> il) :
+            CSequence<CAircraftParts>(il)
+        { }
+
     } // namespace
 } // namespace

src/blackmisc/aviation/aircraftpartslist.h

@@ -39,6 +39,9 @@ namespace BlackMisc
 
             //! Construct from a base class object.
             CAircraftPartsList(const CSequence<CAircraftParts> &other);
+
+            //! Construct from initializer list.
+            CAircraftPartsList(std::initializer_list<CAircraftParts> il);
         };
 
     } //namespace

src/blackmisc/aviation/aircraftsituationlist.cpp

@@ -27,5 +27,9 @@ namespace BlackMisc
             CSequence<CAircraftSituation>(other)
         { }
 
+        CAircraftSituationList::CAircraftSituationList(std::initializer_list<CAircraftSituation> il) :
+            CSequence<CAircraftSituation>(il)
+        { }
+
     } // namespace
 } // namespace

src/blackmisc/aviation/aircraftsituationlist.h

@@ -45,6 +45,8 @@ namespace BlackMisc
             //! Construct from a base class object.
             CAircraftSituationList(const CSequence<CAircraftSituation> &other);
 
+            //! Construct from initializer list.
+            CAircraftSituationList(std::initializer_list<CAircraftSituation> il);
         };
     } // namespace
 } // namespace