Templates site: HTTP Content-Type for hosted templates is application/octet-stream instead of application/vnd.oasis.opendocument.text-template
[This problem may already be known, however, I could not find it in the list of issues here.]
When downloading templates from the templates site at templates.libreoffice.org, the HTTP Content-Type is not of a type that can be handled by LibreOffice such as
application/vnd.oasis.opendocument.text-template, but is a generic
application/octet-stream. Therefore, a browser such as Firefox cannot detect which application to use for opening the document template file. E. g. using Debian GNU/Linux 7.8 (wheezy) with Iceweasel/Firefox 31.7.0, Iceweasel wants to open the file using a text editor, which is not what a user wants it to do.
The template creator can use an external URL for providing the files. Using e. g. an Apache webserver instance, the Content-Type filed is set correctly.
See also the attached files that show the HTTP/TCP stream captured using Wireshark for comparison between templates.libreoffice.org and an external Apache HTTPd.