links: additional dependencies

So, yeah, Links has been using the system OpenSSL for secure connections.

Additional dependencies based on what the configure script recommends, and a mirror, and a test, and style changes.
I've made it connect to DuckDuckGo securely in the test now. I'm not sure if the bot will like it, because I'm not sure whether or not the testing mechanism is deep enough to know that successfully loading the webpage is a successful test? Other than that, I don't think there's much else we can try if that doesn't work.