only permit one video stream per channel
do not send notifications on timer modifications and deletions
added option to wait for first I-Frame
set priority only for the receiver

priority was also set for the device. we can safely use
LIVEPRIORITY for the device.
added cXVDRClient::GetClientName()
removed cSocketLock / use a packetqueue instead
only root may change the priority
Merge remote-tracking branch 'upstream/master'