browser caching

[dodo]

it would be very useful if you could add the cache-control feature like in connect's static middleware, so when the browser have the same data like connect-cache in the cache you don't need to send the data again.

[ghost]

This would be implemented by adding code to recognize the if-modified-since header and return a 304 response code instead of the cached data. I'll make a pull request when I get home.