Minor cleanups in tool-jfed
Minor cleanups in tool-jfed

Make $ma_url a global so we don't always fetch the MA. Remove the
browser check because it is done in jfed.php. Make return array
consistently three elements. Remove commented sample slice_urn.

tcmitchell/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal