Note that we should do the same sort of entity header processing that

Note that we should do the same sort of entity header processing that
HTTP does.

Note that the RTSP RFC talks about packets with no content length,
although it also says they shouldn't exist.

Update a comment now that we *do* handle data that crosses TCP segment
boundaries.

Handle the payload length a bit differently, to make it a bit clearer
what's going on.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@9425 f5534014-38df-0310-8fa8-9805f1628bb7