added --enable-tests also to all cabal install commands.
Added wrappers for little endian and big endian Words in raaz-core
Added endian-wrappers in raaz-hash
Added endian-wrappers in raaz-modular
Added endian-wrappers in raaz-random
Added endian-wrappers in raaz-cipher
Merge LE and BE types for all words fixes #169.