Reimplement --securerandom

Seeds should be reproducable without the flag passed, and unreproducable with the flag passed.
With --securerandom, generate a 9-char alphanumeric string to use to make filenames differ.

Mystery.py

@@ -1,6 +1,6 @@
 import argparse
 import logging
-import random
+import RaceRandom as random
 import urllib.request
 import urllib.parse
 import yaml