sctp: Use AVERROR_BUG instead of abort()

Trying to write to a stream id larger the the maximum requested is
a programming error, still there is no reason to leave a
reachable abort() in the codebase.

CC: libav-stable@libav.org
tls: Support passing old-style tcp options

Make tcp and tls urls near-interchangeable.
tcp: Add AVOption support
rtsp: Check for command strings without spaces

Prevent a NULL-pointer dereference.

CC: libav-stable@libav.org
rtsp: Support tls-encapsulated RTSP
rtsp: Support tls when in listen mode
rtsp: Add rtsps to the probe
lavf: More informative error message

Print the timestamp values and not just the stream index.