In particular add information about the effect of Nagle's algorithm on
early data.

Fixes #3906
Reviewed-by: NBen Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/3955)

spelling: algorithm
spelling: anyway
spelling: assigned
spelling: authenticated
spelling: callback
spelling: certificate
spelling: compatibility
spelling: configuration
spelling: digest
spelling: encrypted
spelling: function
spelling: output
spelling: receive
spelling: renegotiation
spelling: signing
spelling: similar
spelling: string

(Merged from https://github.com/openssl/openssl/pull/3580)Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3580)

SSL_get_max_early_data() recently added by 3fc8d856 ("Construct the
ticket_early_data_info extension", 2017-02-17) is supposed to take an
SSL, but it doesn't.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3113)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)

Change the early data API so that the server must use
SSL_write_early_data() to write to an unauthenticated client.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)

This is for consistency with the rest of the API where all the functions
are called *early_data*.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)

This is for consistency with the rest of the API where all the functions
are called *early_data*.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)

Following on from the latest API changes.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)