Image encoder control - version for OS X/iOS

QImageEncoderControl - implementation for AVFoundation plugin (OS X/iOS,
at the moment iOS >= 7.0).

Change-Id: Ibc2c3ae48252dd4698e263f5abca5c328482d5e7
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

src/plugins/avfoundation/camera/avfimagecapturecontrol.h

@@ -56,6 +56,7 @@ public:
 
     QCameraImageCapture::DriveMode driveMode() const { return QCameraImageCapture::SingleImageCapture; }
     void setDriveMode(QCameraImageCapture::DriveMode ) {}
+    AVCaptureStillImageOutput *stillImageOutput() const {return m_stillImageOutput;}
 
     int capture(const QString &fileName);
     void cancelCapture();