Transformer test UI does not set proper headers

[ktk]

I created an OpenRefine transformer which works fine when I post data via curl. If I try to test the newly registered transformer in the Transformer test-UI it seems that neither the Accept Header nor the Content Type are properly set in the request.

Curl edition (which works):

 curl -XPOST -H "Accept:text/turtle" -H 'Content-Type:text/csv' --data-binary @20141205_AEG_ADL_ALOD_niv_doc-xlsx.csv http://sandbox.fusepool.info:8310\?refinejson\=http%3A%2F%2Fsandbox.fusepool.info%3A8181%2Fldp%2Fbla-json.json

The dialog looks like this:

In BatchRefine log I see:

batchrefine p3 14:14:47.135 [...BatchRefineTransformer] Origin:http://sandbox.fusepool.info:8200 (0ms)
batchrefine p3 14:14:47.135 [...BatchRefineTransformer] Connection:keep-alive (0ms)
batchrefine p3 14:14:47.135 [...BatchRefineTransformer] Content-Type:text/plain; charset=UTF-8 (0ms)
batchrefine p3 14:14:47.135 [...BatchRefineTransformer] Accept:*/* (0ms)
batchrefine p3 14:14:47.135 [...BatchRefineTransformer] Cache-Control:no-cache (0ms)
batchrefine p3 14:14:47.136 [...BatchRefineTransformer] Pragma:no-cache (1ms)
batchrefine p3 14:14:47.136 [...BatchRefineTransformer] ```