some formating cleanup
Raaz.Types: New Rounding class added to remove unsafe CryptoCoerce Instances
Raaz.Primitives: Instances for Rounding class added for conversion between BITS & BLOCKS and BYTES & BLOCKS
Raaz.Util.SecureMemory: Instances for Rounding class added for conversion between BYTES & PAGES
rounding class in raaz-hash
rounding class in raaz-cipher
rounding class in raaz-random
rounding class in raaz-core
Merge added the Round class fixes issue #70.
Added hmac and hmac'
Fixed documentation
Changed Typeable constraint to HasName
Fixed bug in HMAC
Tests for hmac