moved the raaz-primitives directory to raaz-core
updated cabal file
updated the package list in Makefile
update Makefile
update dependency in raaz-hash
reduced the lower bound on integer-gmp and commented the benchmark
added the Raaz/Number.hs module
removed raaz-modular from the modules that are installed
Merge renaming of raaz-primitive to raaz-core partially fixes #126

This is just a renaming. We would like to clean up the package
hierarchy.