Silly Bird Demo Updated!!!

Updated the Silly Bird Demo to make it better reflect the current quality of the main game, and also to make it easier.

Here are just a few of the changes:

• New backgrounds!
• Rooms rebalanced to decrease difficulty
• New rooms added to smooth out difficulty curve
• Changed the music that plays in the sky area
• Updated the engine
• Improved load times
• Improved the web build to make it closer to the downloadable builds
• Rebuilt the demo from scratch to make it easier to update alongside the main game
• Improved scarf performance
• Added more settings
• Added a secret for those who can't resist playing it like it's cookie clicker