Reflecting discussed changes for interpolation performance refs #386

(based on FSX testing)
* Only send changed situation to SIM
* Split sending of parts / situations
* Only send parts with a reduced frequency (means slower as positions)
* Mark geodetic height as null for default values (the value is usually unavailable)
* Fixed altitude to MSL for network data
* Trace which aircrafts support aircraft parts via network
* Renamed insert_fron push_front (as proposed by Roland)

Status quo / lessons learnt
* On slower PCs jitter is still noticed for interpolated aircraft.
* Running interpolation in an independent process (aka core, not in GUI) reduced load dependencies
  => it seems to make sense to run driver in own thread
* The onGround flag in parts seems clumsy as it required to retrieve parts for position updates
* In interpolation performance really matters

src/blackmisc/timestampobjectlist.h

@@ -32,6 +32,9 @@ namespace BlackMisc
         //! List of objects before msSinceEpoch
         CONTAINER findBefore(qint64 msSinceEpoch) const;
 
+        //! Get objects before msSinceEpoch and remove those
+        CONTAINER findBeforeAndRemove(qint64 msSinceEpoch);
+
         //! List of objects before now - offset
         CONTAINER findBeforeNowMinusOffset(qint64 msOffset) const;
 
@@ -67,7 +70,7 @@ namespace BlackMisc
         void sortOldestFirst();
 
         //! Inserts as first object by keeping max. elements
-        void insertTimestampObject(const OBJ &object, int maxElements);
+        void push_frontMaxElements(const OBJ &object, int maxElements);
 
     protected:
         //! Constructor