add an implementation of a timeout handler

[adoublef]

A timeout handler uses ctx to stop a long running process. Here is an examlpe of using a request context.

The current implementation in the Go stdlib does not support Hijack or Unwrap and therefore does not work with the new ResponseController API.

Look into how feasible it be to implement myself.

[adoublef]

In developing my understanding, It seems that the parent context cannot be uncanceled thus even with a http.ReadController having access to set read/write deadline, it isn't going to be doable. I need to observe if omitting some routes will work instead.