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.

ItemList.py

@@ -1,7 +1,7 @@
 from collections import namedtuple
 import logging
 import math
-import random
+import RaceRandom as random
 
 from BaseClasses import Region, RegionType, Shop, ShopType, Location, CollectionState
 from Bosses import place_bosses