Re: How to use attatchment effectively in jester?

[andrea]

I see the same behaviour using 
[Rosencrantz](https://github.com/andreaferretti/rosencrantz), hence I believe 
it is a bug in `asyncfile`.

I tried using a ~50MB file, and the usage grows with every download. It stays 
bounded, though: at around 400MB the GC kicks in and the memory used never 
grows more than 500MB.

For reference
    
    
    import asynchttpserver, asyncdispatch, rosencrantz
    
    let handler = get[
      path("/download")[
        file("test.tar.gz")
      ]
    ]
    let server = newAsyncHttpServer()
    
    waitFor server.serve(Port(8080), handler)