v0.6.0

Each omission now says where it came from: its kind and the document that introduced it (issue #67).
A host that loads a background ontology (BFO and CCO, say) before its own document can tell its own
coverage gaps from the background's in one run, instead of classifying the background alone and
diffing omission strings. The C API and the Rust crate only gain: nothing existing changes shape,
the report lines are byte-identical, and the slop-std-sys 0.5 / slop-rdf-sys 0.6 ranges are
unchanged. An owl:imports that names an attested ontology's version IRI now resolves (issue
#71).

Added

• Omission provenance (SPEC §8.4, issue #67). Every omission of a classify run, of its probe run
  and of an answer run has three things:
  • its kind, the head token of its rendering (MissingDeclaration, UndeclaredProperty,
    UnresolvedImport, SubClassOf, DataAxiom, HasKey, Unrecognized, ...);
  • a MissingDeclaration's entity kind;
  • its document, the index of the document that introduced it in add order (from 0), or none
    when no single document did, for example a MissingDeclaration cited from two documents. The
    probe run's omissions are placed among the input's documents or the probe documents.
  • An axiom stated in two documents is omitted once per copy under el and el++, and each copy
    names its own document. sriq keeps one copy, which names the first document.
  • The document is provenance beside the coverage, never part of an omission's identity. Omissions
    are compared, ordered, deduplicated and hashed exactly as before.
  • C API: howl_run_omission_kind, howl_run_omission_entity_kind,
    howl_run_omission_document; howl_run_probe_omission_kind, _entity_kind, _document,
    _source; the enums types_EntityKind and DocumentSource. Each is total: out of range it
    gives "", entity_class or -1.
  • Rust: Report::omission_details, Report::probe_omission_details,
    Answers::omission_details, each &[Omission] in the order of the matching omissions list;
    the struct Omission { kind, entity_kind, document, text } and the #[non_exhaustive] enums
    EntityKind and Document { Input(usize), Probe(usize) }. All additive.

Fixed

• An import by version IRI resolves (issue #71). OWL 2 lets owl:imports name the imported
  ontology's IRI or its version IRI. An import naming the version stayed an UnresolvedImport, and
  the run inconclusive, even with the document supplied and attested. Now an attested ontology's
  owl:versionIRI, as the supplied documents declare it, counts as attested too, so neither -I
  nor a library host has to know which form each importer used. A version IRI declared by an
  ontology nobody attested still resolves nothing. Pinned by the by-version import golden.