Abnf

* Added RFC 9111.

* Removed changes to RFC 6266 grammar from https://www.rfc-editor.org/errata/eid5383, as that erratum
has been rejected.

* RFC 3986 rule 'Host' now uses first-match alternation as specified.

* Rule.load_grammar now has an option strirt that specifies whether line endings in a source grammar
are fixed.

* Added python 3.11 to tox.

* Added RFC 9110.
https://github.com/declaresub/abnf/issues/13

* Prose-vals that are really rulenames wrapped in angle-brackets are now parsed as rulenames and
become valid rules.
https://github.com/declaresub/abnf/issues/6

* Added RFC 3987.

* Rule.grammar can now be a string. Another decorator load_grammar has been added to load such.

* RFC 7235 (now obsoleted by RFC 9110) no longer modifies the rule 'WWW-Authenticate', as the current parser correctly applies the rule as specified in the grammar.

* Modify grammar following an erratum to RFC 6266 to remove an ambiguity in the grammar.
https://github.com/declaresub/abnf/issues/16

* Implement RFC 6265 rule 'domain-value'.

* Repetition now correctly handles the case self.repeat.min == 0.
https://github.com/declaresub/abnf/issues/15

* Concatenation objects no longer cache parse results. This improves parsing performance significantly.

* Node, LiteralNode objects now use __slots__.

* Alternation.parse now yields matches as found.

* CharValNodeVisitor now visits a node generated by parsing "" correctly.
https://github.com/declaresub/abnf/issues/11

* Implement backtracking. This is potentially a breaking change, given the changes to parsing behavior.
https://github.com/declaresub/abnf/issues/4, https://github.com/declaresub/abnf/issues/10, https://github.com/declaresub/abnf/issues/11 .

* Add grammars for RFC 3339, 3629, 5987, 6266, 9116.

* Modify RFC 5322 rule ‘obs-unstruct’ following RFC errata.

* Fix a bug in Repetition class. Refactoring to remove the use of a flatten function meant that matches
needed to be counted explicitly instead of using the size of the matched nodes list. https://github.com/declaresub/abnf/issues/10

* Add more type hints, and a py.typed file.