[fetch] Introduce Response.body. (#118) (#128)

This change introduces `body` property of Response class. Note that we don't
introduce `Request.body` at this moment and hence some properties and algorithms
defined in the Body mixin are moved to Request and Response.

`bodyUsed` property is now based on `IsDisturbed` defined in the streams spec.
Request.bodyUsed emulates the behavior without using streams.
You can view, comment on, or merge this pull request online at:

  https://github.com/whatwg/fetch/pull/128

-- Commit Summary --

  * Introduce Response.body.

-- File Changes --

    M Overview.html (392)
    M Overview.src.html (390)

-- Patch Links --

https://github.com/whatwg/fetch/pull/128.patch
https://github.com/whatwg/fetch/pull/128.diff

---
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/pull/128