configuration option for SSLv23 or v3 only
wrong rdoc type/tag
avoid relying on the SSL_METHOD const-ness

It is apparently different accross openssl versions
allow multiple versions instead of only forcing sslv3

This introduces a new ssl parameter: :min_version, which can be
:sslv2 (any), :sslv3 (no SSLv2), or :tlsv1 (forces tlsv1).
Merge branch 'force_tls'