Merge pull request #75 from escherba/r_update

some possibly unnecessary micro-optimizations; also add more doc-tests
move commented out code into docstring
try XOR instead of hashing repr; also parametrize seed
parametrize seed, drop use of salt
version bump
Merge pull request #76 from escherba/r_update

parameterize seeds
Merge pull request #9 from escherba/master

parameterize seeds