don't constantly re-seed the random number generator, it's slow
don't constantly re-seed the random number generator, it's slow

This means it behaves slightly differently from pyflann, in that
it doesn't reseed the generator. This should only be an issue if
you're building randomized indices in a multiprocessing pool, in
which case you should explicitly reseed the random state (or pass
random_seed explicitly).

dougalsutherland/cyflann,dougalsutherland/cyflann