Polymer/PointerEvents — pull request #105 by azakus (2013-10-21 22:54:52+00:00)
Title: A few spec compliance changes to pass the w3c tests

- relatedTarget must be null if pointerevent is capturing
- `new PointerEvent(..) instanceof PointerEvent === true`
- Manual tests: http://github.com/w3c/web-platform-tests

Manually verified by using w3c/web-platform-tests#324 and injecting PointerEvents polyfill into each test:
```bash
sed -i '' -e '/testharness.js"/{
a\

}' web-platform-tests/pointerevents/*.html
```