Add Icecast protocol

Icecast is basically a convenience wrapper around the HTTP protocol.

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/allformats.c

@@ -270,6 +270,7 @@ void av_register_all(void)
     REGISTER_PROTOCOL(HTTP,             http);
     REGISTER_PROTOCOL(HTTPPROXY,        httpproxy);
     REGISTER_PROTOCOL(HTTPS,            https);
+    REGISTER_PROTOCOL(ICECAST,          icecast);
     REGISTER_PROTOCOL(MMSH,             mmsh);
     REGISTER_PROTOCOL(MMST,             mmst);
     REGISTER_PROTOCOL(MD5,              md5);