Including C headers inside of `extern "C"` breaks use from C++. Hoist
the includes of standard C headers above the block so we don't try
to mangle the stdlib.
I initially tried to scope this with a targeted change but it's too
hard to do correctly that way. This way, we avoid whack-a-mole.
Firefox is working around this in their e21461b7b8b39cc31ba53c47d4f6f310c673ff2f
commit.
Bug: https://bugzilla.mozilla.org/1953080
Yamaha MusicCast (or at least the RX-A880) seems to be stricter about
the URI here, as it rejects `*`. Examples, such as those documented by
OpenAirplay, use the real URI.
Previously, the content had to be a null-terminated byte
sequence because the sending function used `strlen()` to
determine its length. However, `rtsp_do_auth_setup()` needs
to send a non-textual byte sequence, and it only worked so
far because it did not happen to have any zero bytes in it.
Add a "content_length" parameter and change the type of
"content" to facilitate sending arbitrary byte sequences.
Handle control source io. We don't yet implement retransmission,
though.
Handle latency by exposing the server latency on the stream ports.
Use the Format param event to connect/announce and teardown.
Use the stream state to record/flush.
Fix some leaks.
Remove the state from rtsp-client, we don't need it.
Strip whitespace from header values.
