Before this changed we unconditionally fetched the MimeType. On Some
backends like s3 and swift this takes an extra transaction which meant
that `lsf` on those backends was needlessly slow.
This adds an internal option so `lsf` can declare whether it wants
MimeTypes or not depending on whether the user asked for them and an
external flag `--no-mimetype` for `lsjson`.
See: https://forum.rclone.org/t/reliably-setup-incremental-updates/14006/8
- Change rclone/fs interfaces to accept context.Context
- Update interface implementations to use context.Context
- Change top level usage to propagate context to lover level functions
Context propagation is needed for stopping transfers and passing other
request-scoped values.
This will increase speed for backends which support ListR and will not
have the memory overhead of using --fast-list.
It also means that errors are queued until the end so as much of the
remote will be listed as possible before returning an error.
Commands affected are:
- lsf
- ls
- lsl
- lsjson
- lsd
- md5sum/sha1sum/hashsum
- size
- delete
- cat
- settier
