Merge some cleanup to travis builds.
some more refactoring
some formating cleanup.
documented sha padding.
separated out the blake padding utilities to a separate module.

- Also some cleanup of the routines.
cleanup of sha padding utils.
Merge clean up of padding in the hash package.
fixed the readme
fixed the link to repositories in the cabal files
Merge movement of raaz to the raaz-crypto organisation

The raaz repository is now under the raaz-crypto organisation.  These
patches change the links in the cabal files and readme to reflect this
change.
Added functions to convert hexadecimal bytestring to binary bytestring.