- Mention RFC 2616 conformation in which the server now only sends one
"Transfer-Encoding" header when "chunked" is explicitly set.
- Mention that a timeout handler now sends a 200 status code on
encountering an empty response body instead of sending back 0.

Change-Id: Id45e2867390f7e679ab40d7a66db1f7b9d92ce17
Reviewed-on: https://go-review.googlesource.com/24250Reviewed-by: Andrew Gerrand <adg@golang.org>