shorten added to tests/Modules/Generic in raaz-hash
Functions to test one gadget against another added.
Internal file exporting implementation types and constructors for each hash added to raaz-hash
Tests for hashes testing cportable gadget against reference gadget.
moved back Raaz.Primitives.Hash to raaz-primitives package
got rid of the SafeGadget class and introduced SafePrimitive
hid the HMAC definition
simplified Hash definition
updating raaz-hash
Merge safety now on primitives rather than gadgets fixes #80