qBittorrent 3.3.13

What's new in this version:

Bugfix:
- Fixed UI glitch about torrent numbers in the sidepanel
- Fix downloaded/uploaded columns were not highlighted properly when selected
- Always draw background in files list and search result list
- Remove torrent temp folder if it becomes unneeded
- Remove torrent temp folder when torrent is deleted
- Setup DPI at startup
- Do not attempt to show detailed tooltips without torrent metadata
- Better detection of already present files when adding a torrent
- Fix double click on system tray icon causing program to open and minimize immediately
- BUGIFX: Fix categories sorting in AddNewTorrentDialog
- Set "category" column as case-insensitive in transfer list
- Properly sort categories case-insensitively in filter widget
- Fix renaming files is not case sensitive on Windows platform
- Fix crash in download piece bar
- Fix focusing on the previously opened dialog didn't work

WebUI:
- `RequestParser::splitMultipartData` drop extra trailing newline
- Add `skip_checking` and `paused` to `/command/download` and `/command/upload`
- Fix checkbox hidden
- Implement http persistence connection. Max simultaneous connection limit set to 500. This also release allocated memory of Connection instances at runtime instead of at program shutdown.
- Always send Content-Length header
- Send Date http header
- Fix "Content-Encoding" header is always created
- Implement robust checking for gzip encoding and revise gzip compressing/decompressing code.
- Make the context obligatory for translatable strings. Also delete duplicate strings from extra translations.
- Use translatable strings in Statistics dialog
- Add missing unit sizes in misc.js
- Use the same layout in the Speed tab in preferences as the GUI
- Return status indicating if at least one torrent was successfully added
- Increase the number of digits after the decimal point
- Use less permissive Content Security Policy
- Fix connection status icon too large
- Cosmetic fixes for WebUI upload and download windows
- Fix slow filtering in WebUI
- Make cookie parsing robust
- New API for getting torrent piece info
- Implement Cross-Site Request Forgery defense. Due to this the HTTP referer header is now expected in (almost) all HTTP requests. qBittorrent will drop the request sent without the referer header. That's why we bump the API_VERSION_MIN too.

Search:
- Update demonoid, legittorrents plugins
- Remove mininova, ExtraTorrent plugins
- Add btdb plugin

Windows:
- Updated Spanish, Ukrainian, German, Chinese languages of the installer