Fixes and improvements
- RTSP/RTMP source: fix error 'no one is publishing to path' that happens after some seconds, when sourceOnDemand is enabled (#334)
- RTSP source: apply TCP timeout correctly and reconnect after a timeout (#335)
- RTSP source: build track URLs by using Content-Base when provided by server, fixing many timeouts
- RTSP source: ignore non-standard keys in headers (#336)
- RTMP client: speed up video reading by 1 frame
- RTMP client: speed up acceptance of clients by moving handshake inside client routine
- RTMP client: filter out SPS, PPS and AU NALUs when reading
- RTMP client: avoid "duplicate DTS" error when reading
- RTMP client: do not print errors in case of fragmented AAC frames