setup ecdh and dh params
without it ECDH* and DH* cipher suites  won't work
allow to set cipher list for tls connections
allow to set cipher lists for s2s (s2s_ciphers parameter)
set ecdh and dh params on tls connect too
typo ssl_ctx -> ctx, add null pointer check
Merge pull request #196 from esl/tls-ciphers

support for ecdh* and dh* TLS ciphers