Test for abort and emptied events in HTMLMediaElement.load()

Thanks to Revlin John who submitted a similar test:
https://github.com/w3c/web-platform-tests/pull/571

This started out as improvments to that test, but quickly morphed beyond
recognition in an attempt to provide full coverage.

There's plenty of load() left to test, but that is better left to
dedicated tests since they will require more complex setup to e.g. get
in-band text tracks or seek in the video.
Add blank lines between tests
Stop using /resources/media/sunflower.*

The other media resources are in /media/ and it would be nice to remove
sunflower.* from this odd location. The two modified tests didn't
actually need a moving video, the static movie_5.* is enough.
Merge pull request #635 from foolip/sunflower

Stop using /resources/media/sunflower.*
Merge and expand audio_004.htm and video_001.htm

The existing tests only test that the playing event is fired, also test
that for the other three events fired in the same section of the spec.

This revealed a bug in Blink/WebKit, where canplaythrough is fired before
play and playing.
Remove the remaining overly helpful comments in media tests

Inspired by commit 01462c7520b60f932177617b3a1e23e5809de34d
Merge pull request #637 from foolip/rm-media-pre

Remove the remaining overly helpful comments in media tests
Verify readyState and paused state when autoplaying

Simplify the title to just autoplay since the test is quite general now.
Remove duplicated and broken tests for src attribute removal

This is tested loading-the-media-resource/020.html with much less code.

Also, neither of the removed tests actually work, a local Blink build
where removing the src attribute does invoke resource selection still
passes both tests.
Skip appendChild (media elements need not be in a document to autoplay)
Remove redundant media reflection tests

These are all covered by html/dom/reflection-embedded.html
Remove mysterious audio reflection tests

These tests just look weird, and the spec reference goes nowhere.
[Web Audio] Added Audio API tests: MediaElementAudioSource interface

* Test with source output to OfflineAudioContext
* Test with source output to ScriptProcessor
* Added trimEmptyElements() to helpers.js
Clean up MediaElementAudioSource test

Remove the debugging output, unused tests and clean up some of the
whitespace.
Remove MediaElementAudioSource OfflineAudioContext test

MediaElementAudioSource doesn't make sense in the context of an
OfflineAudioContext, so we'll remove that version of the test.
Tests for MediaElementAudioSource

Merging the changes from #396 with some cleaning up and code review.
Remove out-of-date MANIFEST files for media tests
Minor formatting/editorial tweak to README.
Merge pull request #641 from foolip/rm-manifest

Remove out-of-date MANIFEST files for media tests
cc Removed crufty RDFa test.