Default Secure Streams policy

Similar to how low-level lws provides a default protocol suitable for the common case of http processing that is available is no explicit user protocol is provided, SS provides a simple default policy that is suitable for https connections that are trusted by the system trust store.

This typically requires:

1) Openssl, which is wired up to a trust store 2) Http GET type connections on :443

If you need anything more complicated, you will have to provide your own policy JSON in place of the default one.

The default policy defines a streamtype "__default" that allows overriding ${endpoint} with metadata. What you put here may be just the endpoint address like mysite.com, or it can be a url like https://mysite.com:1234/path, the elements given here control the stream address, port and url path.