Overridable with --user-agent option.
Not yet done for S3 or WebDAV due to limitations of libraries used --
nether allows a user-agent header to be specified.
This commit sponsored by Michael Zehrer.
When quvi is installed, git-annex addurl automatically uses it to detect
when an page is a video, and downloads the video file.
web special remote: Also support using quvi, for getting files,
or checking if files exist in the web.
This commit was sponsored by Mark Hepburn. Thanks!
When there's no extension, don't use "none", but "".
When there is an extension, it starts with a dot, so don't put a redundant
dot in the default format.
