v8.7.0-rc3

Update for 8.7.0-rc3

- Include headers, link libraries and def files (#2).
- Build and distribute 32-bit binaries.
- Add orc dependency.
- Remove GPL fftw3 from the web target.
- Update ImageMagick to 6.9.10-11.
- Update librsvg to 2.44.2.
- Update pango to 1.42.4.