Provisional proxy mode support for pathod.
Collect SSL options into an SSLOptions object

Also split SSL cert specifications from SSL service mode - we can now enter SSL
service mode through a proxy CONNECT request as well.
Proxy mode: drop to SSL if we see an HTTP CONNECT request
CONNECT through proxy mode for pathoc

Also, use this to unit test the pathod CONNECT implementation.
Implement and unit test not-after-connect option.
Docs - pathoc and pathod proxy behaviour