Implement Key-sanity

Still need to add documentation for this mode.

EntranceRandomizer.py

@@ -126,6 +126,10 @@ if __name__ == '__main__':
                              ''', type=int)
     parser.add_argument('--fastmenu', help='Enable instant menu', action='store_true')
     parser.add_argument('--quickswap', help='Enable quick item swapping with L and R.', action='store_true')
+    parser.add_argument('--keysanity', help='''\
+                             Keys (and other dungeon items) are no longer restricted to
+                             their dungeons, but can be anywhere
+                             ''', action='store_true')
     parser.add_argument('--nodungeonitems', help='''\
                              Remove Maps and Compasses from Itempool, replacing them by
                              empty slots.