[from HEAD].
PR: 1230

Submitted by: Alex Lam

twist: server interoperates with non-compliant pre-0.9.8f client.

server interoperates with non-compliant pre-0.9.8f.

twist: server allows for non-compliant Finished calculations in order to
enable interop with pre-0.9.8f.

HelloVerifyRequest [from HEAD].

server accepts even non-compliant encoding in order to enable interop with
pre-0.9.8f clients.

PR: 1578
Submitted by: Charles Longeau <chl@tuxfamily.org>

- no need to disable SSL 2.0 for SSL_CTRL_SET_TLSEXT_HOSTNAME
  now that ssl23_client_hello takes care of that

- fix buffer overrun checks in ssl_add_serverhello_tlsext()

resolve the Valgrind issue with random numbers. Undo the changes to
RAND_bytes() and RAND_pseudo_bytes() that are redundant in this
respect.
Update documentation and FAQ accordingly, as the PURIFY macro is
available at least since 0.9.7.

PR: 521

contents of "buf" when calling RAND_*bytes().

buffer can be normally used.