red: modify the encoder to send RFC 2198

modifies the RED encoder to send the actual RFC 2198 format
described in
  https://tools.ietf.org/html/rfc2198
Decoding is handled in neteq, see red_payload_splitter.h

BUG=webrtc:11640

Change-Id: Ib3005882a3ceee49d2b05c43357f552432a984ac
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176371
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31560}
diff --git a/AUTHORS b/AUTHORS
index 90b6cb7..188503e 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -92,6 +92,8 @@
 Stephan Hartmann <stha09@googlemail.com>
 
 &yet LLC <*@andyet.com>
+8x8 Inc. <*@sip-communicator.org>
+8x8 Inc. <*@8x8.com>
 Agora IO <*@agora.io>
 ARM Holdings <*@arm.com>
 BroadSoft Inc. <*@broadsoft.com>