Shift the gold testing infrastructure into its own module, and add the Haskell program I used to generate the tests.

src/cryptonum/mod.rs

@@ -4,6 +4,8 @@ mod conversions;
 mod complete_arith;
 mod signed;
 mod unsigned;
+#[cfg(test)]
+mod gold_tests;
 
 pub use self::signed::SCN;
 pub use self::unsigned::UCN;