* webpsave: switch to sink_disc
* fix some warnings
* distinguish between animated and single image write
* fix some formatting issues
* add missing comments
* fix webpsave_mime
* don't use sink_disc for single image webp write
* fix potential segv/double free
* update changelog
* remove leftover function declaration
* Revert "don't use sink_disc for single image webp write"
This reverts commit a75922ca93ee8987fa5e1ffc52b68e22bd6fb1fb.
* implement review feedback
* adjust to a column size of 80
* get contiguous RGB(A) buffer directly from VipsRegion
* Revert "get contiguous RGB(A) buffer directly from VipsRegion"
This reverts commit 84fc10e52fb223f0208c605dde92d3f821ceee0e.
* accumulate image data directly in frame_bytes buffer
* switch WebP back to Webp naming scheme
* rename page_index to page_number
* revise formatting
2d9c50735f