Fix randomization

[robgjansen]

The simulator should produce the EXACT same results when run multiple times with the same seed. This currently is broken. Go through and make sure that we only seed the rng once, and that multiple runs produces identical output.

We may need to intercept some functions from the plug-ins to make sure the application randomness goes through our simulator. This will be required for scallion.

[robgjansen]

It seems that tor seeds the OpenSSL random generator by first trying RAND_poll (since it knows about possible other sources of entropy), then by seeding the prng with RAND_seed by reading from /dev/srandom, /dev/urandom, and /dev/random in that order.

see crypto_seed_rng() in tor/src/common/crypto.c

Notes:
OpenSSL randomness:
RAND_seed(), RAND_add(), RAND_poll()

Other:
rand(), srand(), reading from /dev/srandom, /dev/random or /dev/urandom