Added UploadRetainer to let users download a file while it is being
saved in ftp server. UploadProcessor now uses UploadRetainer to retain
info about InputStream so that it can be cloned/reused while another is
used to write the file into the ftp server... DownloadManager now acts
as a download builder, and decides to use a Retained Stream or an FTP
Server Stream. DownloadController now depends and uses DownloadManager.
Ads removed from template.tag!