Editor's draft 20171023.

Merge pull request w3c#1636 from w3c/hta-no-letterbox

Simple text for scaling issue - no letterbox allowed.

Editor's draft 20171002.

Merge pull request w3c#1560 from w3c/setparams-sync-part

setParameters: Do argument checks in sync section and specify parellel steps

Editor's draft 20170822.

Revert to "known good" respec

Editorial: Update change log

Editor's draft 20170605.

Merge pull request w3c#1270 from w3c/respec-v12.2.2

[respec-updater] New ReSpec release

Merge pull request w3c#1239 from fippo/idlnit

RTCIceConnectionEventInit: url is nullable