Lfss

- Improve frontend directory upload feedback.
- Set default large file threashold to 1M.
- Increase default concurrent threads.
- Use sqlite for logging.
- Add vacuum logs.
- Refactor: use dir for directory path.

- Rename api `get_meta` function.
- Frontend support upload directory.
- Fix admin put to non-exists user path.

- Copy file as hard link.
- Add vacuum thumb and all.
- Thumb database use file_id as index.
- improve username and url check with regular expression.

- Inherit permission from path owner for `unset` permission files.
- Add timeout and verify options for client api.
- Bundle small files in memory.