Fix ssl protocol version

This PR tackles two interrelated SSL issues:

- the most important one: starting yaws in embedded mode was ignoring the protocol_version
- given that the first issue is now fixed, application:set_env is only used for <R16B01 where the ssl app was ignoring versions on `ssl:connect` and `ssl:listen`. Reference http://erlang.org/pipermail/erlang-questions/2014-October/081388.html . I am not aware of another reason why `application:set_env` would be preferred/required