Add MJPEG stream support do DVRCamera

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Rename DVRCamera::streamUrl to rstpStreamUrl

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Create MJPEGStream urls

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Reconnect cameras after changing connection type

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>