libavif v0.9.3 release

[Wan-Teh Chang]

Hello everyone,

libavif v0.9.3 has been released. The source code of the release can be
checked out from the git repository[1] using the release tag v0.9.3.

[1] https://github.com/AOMediaCodec/libavif.git

Here is the change log:

[0.9.3] - 2021-10-20

Added
* Support for progressive AVIFs and operating point selection
* Add automatic tile scaling to the item's ispe or track's dims
* Add diagnostic messages for AV1 decode failures
* avifdec: Add PNG compression level arg
* Make image size limit configurable, expose to avifdec
* Add the AVIF_STRICT_ALPHA_ISPE_REQUIRED flag

Changed
* Mandate ispe and disallow zero width or height (#640).
* Re-map libavif speed 7-10 to libaom speed 7-9 (#682)
* Refer to https://aomedia-review.googlesource.com/c/aom/+/140624
* If you were using libaom with the following avif speed setting:
* - speed 0-6: no change is needed
* - speed 7: change to speed 6 for the same results
* - speed 8-9: re-test and re-adjust speed according to your app needs
* Update aom.cmd: v3.2.0
* Update dav1d.cmd: 0.9.2
* Pass TestCase's minQuantizer, maxQuantizer, speed to encoder.
* Regenerate tests.json
* Disable JSON-based tests for now, the metrics are inconsistent/unreliable
* Set diagnostic message for aom_codec_set_option()
* Re-map libavif-libaom speed settings (#682)
* Bump of version in CMakeLists.txt was forgotten
* avifdec: Better message for unsupported file extension
* Do not copy input image when encoding with libaom unless width or height is 1
* Fix the comment for AVIF_STRICT_PIXI_REQUIRED
* Update libavif.pc.cmake (#692)
* In 32-bit builds set dav1d's frame_size_limit setting to 8192*8192
* Allocate alpha alongside YUV (if necessary) during y4m decode to
avoid incorrect alphaRowBytes math
* Change avif_decode_fuzzer to be more like Chrome
* Update codec_dav1d.c for the new threading model
* Generalized ipco property deduplication
* Rename avifParseMoovBox to avifParseMovieBox for consistency
* Simplify idat storage for avifMeta structure (#756)
* Fix oss-fuzz coverage build failure of dav1d
* Redesign AVIF_DECODER_SOURCE_AUTO to honor the FileTypeBox's major brand
* Use "C420" as default Y4M color space parameter