Crossorigin and Credentials for Audio

Hi,

when you creating audio element in code you fix crossorigin to anonymous `audio.crossOrigin = "anonymous";`.

This causes problem with servers, which would require some credentials to be included with requests, value `use-credentials` fixes this problem.
However just using it in all cases will probably break some other uses cases, because then there are more strict rules for URLs and CORS headers. Ideally this should be choice when creating Webamp.

P.S. Thanks for Webamp, it is cool, I have been using winamp for years in past century :-)

Start by locating where the audio element is created and where audio.crossOrigin is assigned. Trace how Webamp configuration is passed into that entry point, then define what option should select anonymous versus use-credentials and verify that existing audio behavior remains unchanged.

Written by the indexing model from the issue text.