[touch-events] Add support for uncancelable touch events (#59)

Touch events (at least in Chrome and Safari) have long been marked `cancelable=false` during an active scroll, or after a touch event timeout has occurred.  This updates the spec to reflect this.

This also adds text describing the relationship with [passive event listeners](https://github.com/RByers/EventListenerOptions/blob/gh-pages/explainer.md).

Fixes #6
You can view, comment on, or merge this pull request online at:

  https://github.com/w3c/touch-events/pull/59

-- Commit Summary --

  * Allow touch events to be uncancelable
  * Tweaks (squash me)

-- File Changes --

    M index.html (32)

-- Patch Links --

https://github.com/w3c/touch-events/pull/59.patch
https://github.com/w3c/touch-events/pull/59.diff

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/touch-events/pull/59