Crypto tests overhaul

So, based on the situation we introduced in #1035 (closed) (someone actually running tests with ./configure --without-ssl), I rewrote the way we look for crypto/tls/https support.

A few things:

1. Introduce a helper in common.js that checks for process.versions.openssl. This could potentially be changed to try importing crypto instead.
2. Review all tests that fail (and the one's that imported tls, https or crypto) to use the new check
3. Unify tests that had their own way of checking for various types of crypto support
4. Have a few tests do partial runs (one or two) -- for instance tests that checks both against http and https servers. These should probably be moved out to their own tests
5. Fix fallout found in for instance testing process.versions (my bad)
6. Avoid style/lint changes as much as possible, but update two tests (2a4a51d) that broke because they imported https while not using it.

Since this affects a lot of files I'd appreciate a quicker feedback round; can see myself rebasing this a fair few times otherwise.