no-ssl2 with no-ssl3 does not mean drop the ssl lib

Reviewed-by: Geoff Thorpe <geoff@openssl.org>
Keep old method in case of an unsupported protocol

When we're configured with no-ssl3 and we receive an SSL v3 Client Hello, we set
the method to NULL.  We didn't used to do that, and it breaks things.  This is a
regression introduced in 62f45cc27d07187b59551e4fad3db4e52ea73f2c.  Keep the old
method since the code is not able to deal with a NULL method at this time.

CVE-2014-3569, PR#3571

Reviewed-by: Emilia Käsper <emilia@openssl.org>
When processing ClientHello.cipher_suites, don't ignore cipher suites
listed after TLS_FALLBACK_SCSV.

RT: 3575
Reviewed-by: Emilia Kasper <emilia@openssl.org>
Fix and improve SSL_MODE_SEND_FALLBACK_SCSV documentation.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Add missing credit.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Configure: add ios64 target.

Reviewed-by: Steve Marquess <marquess@openssl.org>
ecp_nistz256 update.

Facilitate switch to custom scatter-gather routines. This modification
does not change algorithms, only makes it possible to implement
alternative. This is achieved by a) moving precompute table to assembly
(perlasm parses ecp_nistz256_table.c and is free to rearrange data to
match gathering algorithm); b) adhering to explicit scatter subroutine
(which for now is simply a memcpy). First implementations that will use
this option are 32-bit assembly implementations, ARMv4 and x86, where
equivalent of current read-whole-table-select-single-value algorithm
is too time-consuming. [On side note, switching to scatter-gather on
x86_64 would allow to improve server-side ECDSA performance by ~5%].

Reviewed-by: Bodo Moeller <bodo@openssl.org>