note vector fix in changelog 

remove mention of exr save in configure oops

update for newer pandoc "smart" extension is no longer supported for docbook

bump version for animated webp load fix 

allow spng.pc and libspng.ps for libspng discovery 

note HEIC fix in changelog see libvips#1921

fix build with libheif save buit not load We had some definitions inside the #ifdef HEIFLOAD. Thanks estepnv libvips#1844

note render thread change in changelog 

fix write ICC profile to webp ooops, a typo broke ICC profile write to webp 18 days ago thanks augustocdias see libvips#1767

Merge pull request libvips#1756 from libvips/heif-workaround try to work around some broken heic images