MS tests on audio element:
- audio_001* and audio_002* already moved in /html/semantics/embedded-content-0/the-audio-element
- audio_004 and audio_005 already covered by /html/semantics/embedded-content-0/the-audio-element/audio_attributes.html
- fix audio_003
convert audio_001 and audio_002 into reftest
split audio_003 into 1 testharness and 1 reftest
audio_001 and audio_002 share the ref test
rm duplicates
tests refactoring
update ref test title
rm trailing ws
Merge pull request #494 from w3c/deniak/ms-audio

MS tests on audio element