Implement a more secure authentication scheme

[arschles]

#52 implements a crude-but-functional authentication mechanism to fix #17. We did this because we wanted to get some kind of security (even if not complete) into the server. #52 still leaves the claimer susceptible to replay attacks, howevr.

This issue is for adding an auth mechanism that prevents such attacks

[arschles]

punting to RC1. the claimer yet in production and we haven't had much time to work on it during this sprint

[vdice]

ping @arschles this didn't seem to be slated for v2.0-rc1 either -- mind re-assigning as appropriate?

[arschles]

removing from RC1, as this is not critical to the RC