refs #391, allow to send aircraft parts from GUI

* GUI component for aircraft parts
* remote aircraft selector component
* Adjusted GUI for internals component
* Enable / disable debug messages from GUI
* Allow to init engines directly
* Removed unused async sort in sequence

In same step fixed found issues in interpolator
* allow to set max rendered aircraft

src/blackmisc/avcallsign.cpp

@@ -85,6 +85,15 @@ namespace BlackMisc
             return atcAlikeCallsignSuffixes().contains(this->getSuffix(), Qt::CaseInsensitive);
         }
 
+
+        /*
+         * OBS callsign?
+         */
+        bool CCallsign::isObserverCallsign() const
+        {
+            return m_callsignAsSet.endsWith("_OBS", Qt::CaseInsensitive);
+        }
+
         /*
          * Callsign as Observer
          */