Curve Encryption (issue #272)

I don't think this is ready for merging by any means. The unit tests aren't even building on my computer, and I haven't done anything that even vaguely resembles manual testing (I'm trying to figure out how to actually do that...I'm really a total java newb).

But I have something that builds and at least looks like it might have a vague prayer of working correctly, so it did seem worth at least starting the conversation about "Am I in the right general vicinity?"