removed unwanted import of Data.Bits
hlint: stop bitching about module export shortcut
hlint: better names for power of 2 constants
some minor rewriting and cleanup
raaz-modular is once again travis built
criterion version bumps.

The previous version of criterion, i.e. <= 0.8.0.1, was creating
problems with hastache >=0.6 and we had explicitly added additional
constraints to keep hastache down. Now with the new version out, we
bump up the criterion version and lift the bound on hastache.
Added way to parse BE Words
RSA PKCS Signature scheme added
Added Diffie Hellman Key exchange
Added Raaz.DH
integer-gmp version downgraded in raaz-modular
Merge DH and RSA PKCS added.
Fixed lexical error in line break
Merge lexer error in depreciate.