0.1.3 - fix bugs and add unlocking

The following improvements have been made.

1. The better food and fish types are now "locked" until you complete simple objectives.
   1. An "Unlock Everything" button is available in the cheats menu now
2. The collision box at the bottom of the tank has been adjusted to reduce the chance of fish getting stuck
3. The Koi no longer eat basic food pellets as intended
4. Tooltips have been added to the purchase buttons; when locked, they display unlock instructions instead of item descriptions.
5. The Goldfish has left and right "normal" and "hungry" animations.