Test that media constructors behave consistently.

EXPECTED (audioJS instanceof HTMLAudioElement == 'true') OK
EXPECTED (audioJS instanceof HTMLMediaElement == 'true') OK
EXPECTED (audioJS instanceof HTMLVideoElement == 'false') OK
EXPECTED (audioElem instanceof HTMLAudioElement == 'true') OK
EXPECTED (audioElem instanceof HTMLMediaElement == 'true') OK
EXPECTED (audioElem instanceof HTMLVideoElement == 'false') OK
EXPECTED (videoElem instanceof HTMLVideoElement == 'true') OK
EXPECTED (videoElem instanceof HTMLMediaElement == 'true') OK
EXPECTED (videoElem instanceof HTMLAudioElement == 'false') OK
END OF TEST

