Clean up of Storable and CryptoStore instances of SHA1 using parse and write.
Clean up of Storable and CryptoStore instances of SHA224 using parse and write.
Clean up of Storable and CryptoStore instances of SHA256 using parse and write.
Clean up of Storable and CryptoStore instances of SHA384 using parse and write.
Clean up of Storable and CryptoStore instances of SHA512 using parse and write.
Fixing extra import in all SHA HASH types.
Merge use parse and write for hashes fixes #75.

The hash module now uses the Parse monad and Write monoid. It is
expected to clean up the definition of Storable and CryptoStore
instance.
raaz-cipher: fixed bug of wrong ivSize and cleaned code
raaz-random: Added size check test
Documentation fixup in R.P.Cipher.
Using finally to ensure deterministic freeing of memory in withSecureMemory