[w3c/webauthn] c64bda: fix #322: flesh out Security Considerations (for n...

  Branch: refs/heads/master
  Home:   https://github.com/w3c/webauthn
  Commit: c64bdaf2f6b026369729e553b6008d4830e61993
      https://github.com/w3c/webauthn/commit/c64bdaf2f6b026369729e553b6008d4830e61993
  Author: =JeffH <mobileuser@kingsmountain.com>
  Date:   2018-01-10 (Wed, 10 Jan 2018)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  fix #322: flesh out Security Considerations (for now) (#705)

merging this per discussion on today's webauthn call.  @agl & @leshi: please submit discrete issues for the items you identified above. thx. 

commits:
* consolidate sec cons sections, create priv cons

* update FIDOSecRef URL to point to latest rev

* add FIDOAuthnrSecReqs ref, minor editorials

* expand WebAuthn client dfn, compose sec cons intro ref'g FIDOSecRef and FIDOAuthnrSecReqs

* fix AttestationNotPrivateError linking error, thx angelokai!

* fix [[DiscoverFromExternalSource]] link error, thx AngeloKai!

* address emlun's feedback, thx!

* merge from master and fix conflicts