v0.12 - Bugfixes

Additional small bug fixes, nothing major;

• Further tweaked the prices of the special spells. It's now becoming a problem that it's possible to purchase everything and have no use for money anymore, which is kinda why the price was originally so high. That just means I need to add more symbols and spells though.
• Tweaked the flexibility of some sigils - some more rigid, and some more flexible. Trying to minimise incorrect interpretations.
• Once purchased, items will never appear in the shop again (they used to sometimes, and allowed for duplicates)

Yep, that's it.