File upload with CORS (cross origin resource sharing)

[Piotrek Koszuliński]

As mentioned in ​http://docs.ckeditor.com/#!/guide/dev_file_upload

You can also add custom request headers or set flags for the default request. This is especially useful for enabling Cross-Origin requests. For more information about Cross-Origin Resource Sharing see here:

editor.on( 'fileUploadRequest', function( evt ) {

var xhr = evt.data.fileLoader.xhr;

xhr.setRequestHeader( 'Cache-Control', 'no-cache' ); xhr.setRequestHeader( 'X-CUSTOM', 'HEADER' ); xhr.withCredentials = true;

} );

This seems to be a pretty common case and it does not require lots of code, so I would consider adding an option for it. WDYT?