RTSP Improvements

[knight-of-ni]

This is primarily for myself so I don't forget to work on these. Generally, I know how to fix them, but I need time to stumble through my lack of c++ knowledge.

• RTP-Info field should be made non-fatal. Not all cameras send this information, and it can work without it.
• Zoneminder checks for the RTSP timeout after the SETUP command is sent, which it should. However, some devices don't send the timeout value until after the PLAY command is sent. Add a second check for the timeout and update the value if it = 0.
• Add SDP MediaType of "application". This media type is an extra metadata stream the camera can send. ZoneMinder does not need to read this stream, but it does need to know a little about the stream so it does not abort. Grandstream firmware supports this mediatype.
• Fix the following bug in the RTSP logic.
  The current RTSP logic does not support RTP-Info that contains more than one stream. According to RFC2326, multiple streams can be sent like so:

RTP-Info: url=rtsp://foo.com/bar.avi/streamid=0;seq=45102;rtptime=972948234,
url=rtsp://foo.com/bar.avi/streamid=1;seq=30211;rtptime=972948234

Zoneminder currently (always) uses the sequence and rtptime from the second stream, which naturally is not correct if the first stream is the one that is being viewed.

[knight-of-ni]

This issue has been resolved. Closing.