Updating logic and features to better match VT26

Updates include:

* Allow acticating tablets with hammer
* Remove 1/4 magic from the normal mode pool
* Incorporate OHKO compatible cape/cane-of-byrna requirements
* Upgrade Mirror Shield, Progressive Shield, and Bug Catching Net to
qualify as advancement items
* Allow Mirror shield as alternative to cape/byrna for Laser Bridge
* Prevent Waterfall Fairy from upgrading Boomerang or Shield
* Change PoD key logic to match VT26.
* Add restrictions on small key placement (to match VT26). I think these
restrictions may be redundant, but I'm adding them just in case any of
them are not.

BaseClasses.py

@@ -372,6 +372,18 @@ class CollectionState(object):
                 else:
                     self.prog_items.append('Power Glove')
                     changed = True
+            elif 'Shield' in item.name:
+                if self.has('Mirror Shield'):
+                    pass
+                elif self.has('Red Shield'):
+                    self.prog_items.append('Mirror Shield')
+                    changed = True
+                elif self.has('Blue Shield'):
+                    self.prog_items.append('Red Shield')
+                    changed = True
+                else:
+                    self.prog_items.append('Blue Shield')
+                    changed = True
 
         elif event or item.advancement:
             self.prog_items.append(item.name)