RT2751: Declare get_issuer_sk() earlier.

Add a declaration for get_issuer_sk() so that other
functions in x509_vf.c could use it.  (Planned work
around cross-certification chains.)
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Fixed out-of-bounds read errors in ssl3_get_key_exchange.

PR#3450

Reviewed-by: Emilia Käsper <emilia@openssl.org>
Add support for Camellia HMAC-Based cipher suites from RFC6367

While RFC6367 focuses on Camellia-GCM cipher suites, it also adds a few
cipher suites that use SHA-2 based HMAC that can be very easily
added.

Tested against gnutls 3.3.5

PR#3443

Reviewed-by: Tim Hudson <tjh@openssl.org>