Threading implementation:
-StreamTools now inherits from AvTools AND from QThread
-(StreamTools become a Qthread)
-The captureVideo(..) function is executed as a QThread in the run function, which is the one executed as a thread
-The pointer of the ffmpeg process is now a global attribute
-When the application stops before the end of the ffmpeg process,the process is killed
-Life is good ! :)

Signed-off-by: Nans Plancher <nans.plancher@gmail.com>