add original error from exception to failCallback function
add original error from exception to failCallback function

murtaza-nathani/jquery.fileDownload,johnculviner/jquery.fileDownload,lmario07/jquery.fileDownload,johnculviner/jquery.fileDownload,murtaza-nathani/jquery.fileDownload,javi-moralesf/jquery.fileDownload,javi-moralesf/jquery.fileDownload,johnculviner/jquery.fileDownload,lmario07/jquery.fileDownload