WIP: Fix TLS 1.2 tests
This shouldn't change anything as of yet. It adds support for running the GnuTLS tests under TLS 1.2, but disables it with a comment because it's broken currently. The goal of #94 (closed) will be to uncomment this. Disregard, I've solved it. :)
I've also removed one level of indentation here by changing the way we skip DTLS tests under OpenSSL.