Add Item functionality setting and progressive bow

Progressive bows still have issue for silvers hint

README.md

@@ -348,6 +348,12 @@ Select the game completion goal. (default: ganon)
 
 Select the game difficulty. Affects available itempool. (default: normal)
 
+```
+--item_functionality [{normal,hard,expert}]
+```
+
+Select limits on item functionality to increase difficulty. (default: normal)
+
 ```
 --timer [{none,display,timed,timed-ohko,ohko,timed-countdown}]
 ```