Use document.body

Have we forgotten?
Use ES5 getters, setters and Object.create instead of __proto__ etc

This fixes pure JS issues with IE9+
Merge pull request #120 from arv/es5-proto

Use ES5 getters and setters as well as __proto__ where available.
Rename Timeline.createPlayer() to Timeline.play()
Rename Player.timedItem to Player.source
Merge pull request #127 from steveblock/renaming

Renaming
Fix Player.currentTime to return the effective current time
Fix Player.startTime when Timeline is not started
Fix unpausing
Merge pull request #128 from steveblock/playPause

Update some Player behaviour to match latest spec
Merge pull request #123 from Krinkle/patch-1

Use document.body
Adds support for dynamically loading the polyfill by setting up 0 times if the document is already loaded at the time the polyfill script is processed.
This is done by checking document.readyState == 'complete'.
Add warning for dynamic loading in the absence of performance timing. In this case, document zero time is incorrect.
Warn the user about document zero time only if the polyfill is loaded dynamically and performance timing is unavailable.
Merge pull request #129 from sorvell/master

Add support for dynamically loading polyfill (after document has loaded).
Remove Player.cancel()

See https://github.com/web-animations/web-animations-js/issues/136
Remove superfluous and unimplemented TimedItem.seek()
Remove superfluous TimedItem.reverse()

This functionality will probably be moved to Player.reverse(). See
https://github.com/web-animations/web-animations-js/issues/137
Fix AnimationGroup.clear()

Also remove superfluous TimedItem.clear()
Merge pull request #138 from steveblock/specUpdates

A few bug fixes and updates from the last meeting