Last Four Potions for New Pet System from Lemoness

- Updated pet egg sprite sheet image with 4 new potions that Lemoness made
- Updated PetEggs.css with positions of new pots

Please note: 
- I commented out the previous stop gap solution for missing images. Feel free to modify or delete at your leisure.
- I had to extend the sprite sheet image file by 3 pixels at the bottom because a potion was taller than the rest and the pet egg tiles. This is also reflected in the CSS for that item. It shouldn't be an issue until we add more under that potion and even that can be managed. Could affect inventory alignment if programmer is expecting an exact potion height.