Added testPokePeek
hlint cleanup
refactored the padLength and shaPadding
changed sha hashes to use refactored padLength and padding
refactored sha1 trans function
Merge cleanup raaz-hash

- hlint fixups and associated refactoring
- refactoring padLength and padding of sha hash family
document the Hash class
added the HMAC primitive
removed some unwanted imports from R.P.Hash
added length safe version of replicate function
some code and documentation cleanup
added memory buffer to hash cryptographic hashes
added gadget instance for HMAC