new qt5 qml GL video sink

new qt5 qml GL video sink

Very much in the same spirit as the Gtk GL sink

Two things are provided
1. A QQuickItem subclass that renders out RGBA filled GstGLMemory
   buffers that is instantiated from qml.
2. A sink element that will push buffers into (1)

To use
1. Declare the GstGLVideoItem in qml with an appropriate
   objectName property set.
2. Get the aforementioned GstGLVideoItem from qml using something like

QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

QObject *rootObject = engine.rootObjects().first();
QQuickItem *videoItem = rootObject->findChild<QQuickItem *> ("videoItem");

3. Set the videoItem on the sink

https://bugzilla.gnome.org/show_bug.cgi?id=752185