Add a proxy that will trace method calls to the resource.
Adding more to the resource proxy.
Use string keys which will make lookups easier.
Add some place to store recorded traces.
We'll be adding logging/tracing shortly.
Add X- header for trace ID.
Method#source_location is not available on 1.8.x.
Need to remove the spec for it as well.
Add spec for trace stores.
Cleanup whitespace.
Trace resource calls and decisions.

* Whether to trace depends on the return value resource's #trace?
  method. More global tracing can be added later.
* Remove use of class << self in Trace module.
* Add Trace::FSM module that is injected into the Decision::FSM when
  tracing is enabled. Decisions are no longer recorded when tracing is
  disabled.
* Moved a lot of common resource-related setup into a shared context.
* Added a spec for the Trace module.
WIP Reel adapter. [ci skip]
Fix chunked response bodies through the rack adapter.

Fixes #44
Assert proper Transfer-Encoding header is set
Actually chunk the response body. :P
Don't stream strings in ruby 1.8. Stream callables.
Skip Rack::Response, which reads the entire response body.
Ensure non-chunked response bodies are enumerable for rack.
Import static files from Erlang webmachine.
Fixing Reel adapter.

- Ensure callback only runs when connection has a request.
- Pull 'Host' header out with fetch to bypass transform_key.
- Reference correct variable in body-prepping case statement.