Add RSA fault attack functions

[unicornsasfuel]

While I don't see there being a crazy amount of real-world usage of RSA fault attack functionality (hey, I could be wrong!) it is a popular CTF problem, since you can provide a series of faulty signatures in a text file and not have to deal with server costs or hassles. It's also a problem with many faces: If p or q get corrupted during RSA-CRT, a little GCD magic is enough to recover the private component. However, if d or N get corrupted, the math gets more complex.

I've already got a prototype RSA-CRT fault attack function written, and there are a few recent writeups describing the problem and solution with d corruption thanks to the problem's inclusion in the recent CSAW CTF, so I should be able to take a look at a few reference implementations for solutions and write one, especially considering one of them includes a set of captured faulty signatures.