New libavif 0.9.1 apply some very strict standard compliance
checks by default. Unfortunately, it rejects many files made by
libheif-based apps (GIMP, ImageMagick) in the past.
libheif 1.12.0 (released on May 5, 2021) addressed the problem,
but it would be good to extend grace period, allowing other
projects and distributions to upgrade to fixed version.
Allow saving Qt-unsupported variants of ICC profiles, they could be
correctly handled by apps with wider color management support.
Change way how QColorSpace is created to avoid
rare problems in some apps.
Due to various double vs float arithmetic,
some primaries could be rejected by Qt.
If necessary, we adjust the values so they
will be accepted by Qt.
Remove newline from the ends of error strings.
