Blowfish128 against latest cryptocipher

If we end up needing to make a cryptocipher-crypto-api package, this
should probable move there, along with the new datatypes/instances for
AES.
Wrapper around CPRG

Need to hide the broken CPRG class from users.  Wrap CryptoRandomGen so
it will work (with a newtype) and *very carefully* check all uses so
that we can propogate errors properly.
Switch blowfish support to cipher-blowfish