Update CryptoJS to v3.1.

* Resolves http://code.google.com/p/crypto-js/issues/detail?id=47
Use CryptoJS for converting between Typed and WordArrays
Revert "Use CryptoJS for converting between Typed and WordArrays"

This reverts commit 6a44e07ea05c5152bf43d84163a6063ce92e0ed7.

* Their solution is actually slower than mine. Maybe they'll make a faster one in the future.
Explain why I'm not using lib-typedarrays.js in source.