Need to ditch the tiled background

[city41]

The tiled background is causing a lot of performance problems with no real benefit. It can also be seen as a little unfair since Impact has prerendering of layers to get around this.

For now, the Lime version can be ran with 'notile' in the URL to use a prerendered background, ala:

http://city41.github.com/breakouts/limejs/index.html?notile

[city41]

All three implementations now support either a prerendered background (the default) or the use of tiles.

To turn on tiles, add "usetiles" to the URL, for example:

http://city41.github.com/breakouts/craftyjs/index.html?usetiles