Release v0.21.1 - A fairly important bugfix backport - Fixed a potentially memory safety issue in the hdr and tiff decoders, see #885 - See [the full advisory](docs/2019-04-23-memory-unsafety.md) for an analysis - Fixes `ImageBuffer` index calculation for very, very large images - Fix some crashes while parsing specific incomplete pnm images - Added comprehensive fuzzing for the pam image types