* when accessing files inside an xdev volume, verify that the file
exists on the same device/filesystem as the volume root
* when accessing files inside an xvol volume, verify that the file
exists within any volume where the user has read access
* when deleting files, do not cascade upwards through empty folders
* when moving folders, also move any empty folders inside
the only remaining action which autoremoves empty folders is
files getting deleted as they expire volume lifetimes
also prevents accidentally moving parent folders into subfolders
(even though that actually worked surprisingly well)
* winscp mkdir failed because the folder-not-found error got repeated
* rmdir fails after all files in the folder have poofed; that's OK
* add --ftp4 as a precaution
mainly motivated by u2cli's folder syncing in turbo mode
which would un-turbo on most dupes due to wrong lastmod
disabled by default for regular http listings
(to avoid confusion in most regular usecases),
enable per-request with urlparam lt
enabled by default for single-level webdav listings
(because rclone hits the same issue as u2cli),
can be disabled with arg --dav-rt or volflag davrt
impossible to enable for recursive webdav listings
...when continuing into the next folder
accidentally introduces a neat bonus feature where the music
no longer stops while you go looking for stuff to play next
* mostly deprecate --http-only and --https-only since there is zero
performance gain in recent python versions, however could still be
useful for avoiding limitations in alternative python interpreters
(and forcing http/https with mdns/ssdp/qr)
* mention antivirus being useless as usual
prevents running out of FDs thanks to thousands of sqlite3 sessions
and neatly sidesteps what could possibly be a race in python's
sqlite3 bindings where it sometimes forgets to close the fd