IE11: unload() for html5 audio initiates a new request + results in console error.

[aroth]

IE11 on Windows 7

Calling unload() on a Howl object created with html5: true is causing IE to make a new request to / which often results in the error:

MEDIA12899: AUDIO/VIDEO: Unknown MIME type.

This error is due to the fact that IE has associated a media content type with sounds[i]._node and the content returned from the new request is coming back as text/html.

The new request is triggered by this line in #unload:

sounds[i]._node.src = '';

Is it necessary to set src to an empty string? And if so -- can it be done in a way that doesn't result in a new request?

See the image below for a full walk through:

[goldfire]

Thanks, 745a726 should fix this.