tls: more secure defaults

This updates the default cipher suite to an more secure list, which
prefers strong ciphers with Forward Secrecy. Additionally, it enables
`honorCipherOrder` by default.

Noteable effect of this change is that the insecure RC4 ciphers are
disabled and that Chrome negotiates a more secure ECDHE cipher.

Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Fedor Indutny <fedor@indutny.com>
PR-URL: https://github.com/iojs/io.js/pull/826