- Ensure vsync is instantiated before extensions (ampproject#942)

  - Promise.all polyfill (ampproject#935)
  - fix gulp autofix (ampproject#932)
  - Separate tools distribution from the rest (ampproject#929)
  - Set cookie for the root path and update description (ampproject#928)
  - Experiments.html page for our CDN (ampproject#923)
  - Case-insensitive sanitizing of attribute values (ampproject#917)