The current limit of 2^14 bytes is too low (e.g. RFC 5246 specifies the
maximum size of just the extensions field to be 2^16-1), and may cause
bogus failures.

RT#4063
Reviewed-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/413)