Pleco Chinese Dictionary for PC

- Adopted new HWR + OCR libraries by default, including for live OCR, though you can revert to the old ones in settings
- Adopted better/streamlined "new OCR" interface by default for live OCR, though with the new algorithm it's a bit different (we show text above the box rather than as an overlay because ML text rects are less accurate)
- Added 'snap OCR' for quick captures of text to tap-lookup
- Switched to open-source PDF library and cleaned up some PDF reading annoyances
- Many bug fixes