More of Retro Mode

Implement correct Retro Mode item pools.
Set up most of the key logic to handle retro mode (still needs shop access)
Set ROM flags appropriately.
TODO: Support Retro Mode with custom item pools, deal with shops in general, deal with Bow paired with arrow requirements, correct Expert item pool for silvers, test older fill algorithms with retro mode, deal with the new Sahas/Bomb Shop reveal map info ROM flags.

Items.py

@@ -157,7 +157,7 @@ item_table = {'Bow': (True, False, None, 0x0B, 'You have\nchosen the\narcher cla
               'Big Key (Ganons Tower)': (False, False, 'BigKey', 0x92, 'A big key to the evil tower', 'and the big key', 'the big-unlock kid', 'big key for sale', 'face key fungus', 'key boy opens chest again'),
               'Compass (Ganons Tower)': (False, True, 'Compass', 0x82, 'Now you can find Agahnim!', 'and the compass', 'the magnetic kid', 'compass for sale', 'magnetic fungus', 'compass boy finds boss again'),
               'Map (Ganons Tower)': (False, True, 'Map', 0x72, 'A tightly folded map rests here', 'and the map', 'cartography kid', 'map for sale', 'a map to shrooms', 'map boy navigates again'),
-              'Small Key (Universal)': (False, False, 'SmallKey', 0xAF, 'A small key for any door', 'and the key', 'the unlocking kid', 'keys for sale', 'unlock the fungus', 'key boy opens door again'),
+              'Small Key (Universal)': (False, True, None, 0xAF, 'A small key for any door', 'and the key', 'the unlocking kid', 'keys for sale', 'unlock the fungus', 'key boy opens door again'),
               'Nothing': (False, False, None, 0x5A, 'Some Hot Air', 'and the Nothing', 'the zen kid', 'outright theft', 'shroom theft', 'empty boy is bored again'),
               'Beat Agahnim 1': (True, False, 'Event', None, None, None, None, None, None, None),
               'Beat Agahnim 2': (True, False, 'Event', None, None, None, None, None, None, None)}