[w3c/webauthn] 9636ca: Various minor technical fixes (#147)

  Branch: refs/heads/master
  Home:   https://github.com/w3c/webauthn
  Commit: 9636ca2600c11d28aa124eb0ff1b121d8b8f9f9e
      https://github.com/w3c/webauthn/commit/9636ca2600c11d28aa124eb0ff1b121d8b8f9f9e
  Author: Vijay Bharadwaj <vijaybh@users.noreply.github.com>
  Date:   2016-07-27 (Wed, 27 Jul 2016)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Various minor technical fixes (#147)

* Secure context requirement: SHOULD -> MUST

Fixes #146

* clientDataJSON is returned in WebAuthnAttestation (top-level attestation structure), not AttestationStatement (packed attestation)

Fixes #119

* After successful makeCredential or getAssertion, cancel outstanding requests to other authenticators

Fixes #124

* Correct length of packed attestation

Fixes #33

* Stamp out references to KeyHandle

Fixes #31

* Simplify description of packed attestation rawData

As per feedback from @equalsJeffH - thanks!