primitives should be built before tests
getting rid of fillUp and fillUpChunks

Use the stuff coming from Raaz.ByteSource instead.
renamed startCxt to startHashCxt
exposed a rudimentry MAC module
added rfc2104 for mac construction
added the HMAC datatype and instances for BlockPrimitives and HasPadding
added MAC instance for HMAC
Merge branch 'x-primitives'

Merging MAC module with HMAC construction
renamed startCxt to startHashCxt every where

This is due to change in the name in the raaz-primitives package.
Merge branch 'x-hash-sha'
functions computing the mac of bytesource, bytestrings and file
moved HMAC definition from R.MAC to R.Hash
removed unnecessary definition of oneblock
got rid of the extra parameter for startHashCxt
got rid of the extra parameter for toMACSecret
removed extra arg for startHashCxt