* craft-psd: Photoshop PSD/PSB reader and writer, moved from PhotoCraft
PhotoCraft's `photocraft-psd` crate (crates/psd at storytold/photocraft
63b641b55e54bf8f5c83efd977fdb16a2c255431) as `craft-psd`: the lossless
PSD/PSB model, reader, writer and builder, descriptors, the Photoshop
resource files that share its primitives (.abr, .asl, .aco, .act, .ase,
.grd, .pat, .atn, .csh, .shc) and the Photoshop blocks of a layered TIFF.
The crate had no dependency on any other PhotoCraft crate.
Code is unchanged apart from the crate name, craft-libs' rustfmt width,
comments that named other PhotoCraft crates, issue references (now
`photocraft#N`), and the corpus tests' directory (`CRAFT_PSD_CORPUS` or
`corpus/` at the workspace root). Tests, proptests, fuzz targets and
fixtures move with it.
Part of #778, #786.
* craft-psd: Head reads the header and image resources without layers or pixels
`Head::from_bytes` takes the file or a prefix that reaches the end of the
image resources; `Head::from_source` makes three reads and nothing after
the resources. `Header::from_bytes` parses the 26-byte header alone, and
`head::sniff` checks the signature.
The readers in LightCraft (header probe, EXIF/XMP scan), DesignCraft and
FilmCraft skip the layer section and work from the start of the file.
`PsdFile` parses every layer record, and `Header::read` was private, so
they had no equivalent here.
Section lengths past the data are errors before anything is allocated.
Dylan M. Taylor
c972d5fc29