fileDownloadSetup, frameId and fail reason cookie

Base 1.4.2 plus:
*  Create $.fileDownloadSetup to support default configurations
https://github.com/austinjones/jquery.fileDownload/commit/78da2fa10c9c4d72a6d234141c18a3684ef4af28
*  Return fail reason cookie
https://github.com/mattiamascia/jquery.fileDownload/commit/974a8f1f04a00440fbf38c832c43e74b2c7499d2
*  FrameId support for multiple downloads
https://github.com/mattiamascia/jquery.fileDownload/commit/974a8f1f04a00440fbf38c832c43e74b2c7499d2
fix bugs from previous version