Requests and responders enumerate their bodies.
Servlet backend.
Stream example.
Echo example.
Raw /echo for benchmarking.
Parameterize chunk size.
Remove chunk extensions.

Chunk extensions are:
- not accessible to servlets.
- not accessible in Netty's HTTP decoder.
- deprecated in the draft of HTTPbis:
  http://trac.tools.ietf.org/wg/httpbis/trac/ticket/343

This sheds a wrapper for something we don't use.