Add BIO_bind function to bind local address for a socket.

Add BIO_bind function to bind local address for a socket.

Add -bind option to s_client application to allow specification of
local address for connection.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5272)