[w3c/webauthn] a47fe1: Switch |tokenBindingId| to a structure.

  Branch: refs/heads/master
  Home:   https://github.com/w3c/webauthn
  Commit: a47fe1c4d53b123caa7abc76e9659b95dc1c1a16
      https://github.com/w3c/webauthn/commit/a47fe1c4d53b123caa7abc76e9659b95dc1c1a16
  Author: Adam Langley <agl@imperialviolet.org>
  Date:   2018-02-14 (Wed, 14 Feb 2018)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Switch |tokenBindingId| to a structure.

The existing string was not able to express the ternary nature of token
binding for a given connection. See referenced bug for discussion.

Fixes #798


  Commit: 8b8e9ecb6c388e6a46c51a768464aa99477a5942
      https://github.com/w3c/webauthn/commit/8b8e9ecb6c388e6a46c51a768464aa99477a5942
  Author: Adam Langley <agl@imperialviolet.org>
  Date:   2018-02-14 (Wed, 14 Feb 2018)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Address @emlun comments.


  Commit: 05335d4484044dbca552f74ab52ff171ebb71b34
      https://github.com/w3c/webauthn/commit/05335d4484044dbca552f74ab52ff171ebb71b34
  Author: Anthony Nadalin <tonynad@microsoft.com>
  Date:   2018-02-16 (Fri, 16 Feb 2018)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Merge pull request #802 from agl/issue798

Switch |tokenBindingId| to a structure.


Compare: https://github.com/w3c/webauthn/compare/e3c1ad491caa...05335d448404