Tag Ristretto 0.3.3

- Fix bug #8343 (Do not use symbols from gtk+ > 2.20)
- Autogenerate Changelog on make dist
- Update scale information when box-zoom is used.
- Fix bug #8317 (Blurred full-screen image) - round offset to nearest
  pixel.
- Fix --fullscreen and --slideshow CLI options.
This tag has no release notes.