That trailing slash is needed for legacy chunked mode, because it puts the
chunks in a subdir under the key. But, outside legacy chunked mode, it's BS
and it's amazing it worked at all with some webdav servers.
This speeds up the webdav special remote somewhat, since it often now
groups actions together in a single http connection when eg, storing a
file.
Legacy chunks are still supported, but have not been sped up.
This depends on a as-yet unreleased version of DAV.
This commit was sponsored by Thomas Hochstein.
