changes from 19/2/2012:
Changelog:
2014.02.19:
- Fixed a bug that was causing some bytes to be deleted when receiving H.265/RTP streams.
  (Thanks for Michel Promonet for bringing this to our attention.)
- Added support for streaming Opus audio tracks from Ogg files.  Also updated "OpusFileSink"
  (which is used by "openRTSP") to write Opus audio streams into Ogg-format files.
- Updated the "ProxyServerMediaSession" implementation - and thus the "LIVE555 Proxy Server"
  to support proxying of Opus audio RTSP/RTP streams.
- Added a "test.opus" file option to the "testOnDemandRTSPServer" demo application.
- Made minor changes to "OggFileParser.cpp" to eliminate compiler warnings on some platforms.