Send ctrls to EVP_PKEY_METHOD during signing of PKCS7 structure so
customisation is possible.

PR: 1071

EVP_PKEY_cmp().

large FD: it's non-blocking mode anyway

only chance for T[ed]4 to get evicted in this module is when its cache
"overlaps" with last 128 bits of key schedule.

prefetch could have been moved closer to Td4 references. Something for
later consideration...

the source.

CRYPTO_get_idptr_callback(), CRYPTO_thread_idptr() for a 'void *' type
thread ID, since the 'unsigned long' type of the existing thread ID
does not always work well.

Put ECCdraft ciphersuites back into default build (but disabled
unless specifically requested)

the BN library more generally useful.

Submitted by: Douglas Stebila

Also, change the default ciphersuite to give some prefererence to
ciphersuites with forwared secrecy (rather than using a random order).