Implement 'honor_cipher_order' SSL server-side option

HonorCipherOrder as implemented in Apache, nginx, lighttpd, etc. This
instructs the server to prefer its own cipher ordering rather than the
client's and can help protect against things like BEAST while
maintaining compatability with clients which only support older ciphers.

Currently this branch does not include any tests, due to time constraints on my end, but I would appreciate a code review because we may ship this patch along with the next Riak release.