Add sticker book to backroom

[Poobslag]

• Add a way to get stickers (maybe a girl who gives you a sticker for every 10 frogs you find)
• Add a way to add your stickers to a sticker book
  • draw a big background area (but allow for multiple in the future)
  • add a drag-and-drop interface for putting your stickers in the book
  • add a paging interface for flipping through pages of frogs
  • add a way to toggle the frog's pose
  • create 'backgroundless' frog pictures