Revise OpenSSL fix to work with OpenSSL 1.0.0beta*

In brief: you mustn't use the SSL3_FLAG solution with anything but 0.9.8l,
and you mustn't use the SSL_OP solution with anything before 0.9.8m, and
you get in _real_ trouble if you try to set the flag in 1.0.0beta, since
they use it for something different.

For the ugly version, see my long comment in tortls.c