QtGStreamer support for displaying video in the QML (QtQuick 2) version of the PFD

This branch has experimental code for using QtGStreamer to stream media (video/audio) to a Qt QML or QWidget. The code contains changes for the 'PrimaryFlightDisplayQML' and the 'HUD' (highly experimental) version of the flight display. 

There is a dependency on QtGStreamer, GStreamer.  (http://gstreamer.freedesktop.org/modules/qt-gstreamer.html)
This version was compiled with GStreamer 1.4.3 and QtGStreamer 0.10.1
QtGStreamer also has a dependency on Boost.  

These dependences were not added to QMake. If it's decided to pull this code, the make files will need to include dependency checks for theses libs.