not use RTPDemuxContext, but rather take a pointer to the payload context
directly. This allows using payload handlers regardless over the transport
over which they were sent, and prepares for the introduction of a future
RDTDemuxContext. See discussion in "RDT/Realmedia patches #2" thread on ML.



git-svn-id: file:///var/local/repositories/ffmpeg/trunk@15541 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b