Extract methods and properties do LiveStream interface

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Don't use RTSPStream classes outside DVRCamera class

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Add connection type configuration

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Use LiveStream in DVRCamera

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Add MJPEG stream support do DVRCamera

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