Hatching Potions from Lemoness, Pet Egg CSS, Ethereal lion mount.

* Added the hatching potions from Lemoness to the pet egg CSS sprite sheet.
* Updated PetEgg CSS to include positions for hatching potions.
* Added Ethereal Lion mount to mount sprite sheet.

Not sure what this views/static/extensions.html change is. It's not one that I made so discard, ignore or what have you.