Legacy support, what is the specification?

The function `parse_http_version` does not accept versions below HTTP/1.0. However `parse_headers` allows only LF to mark the end of header:
https://github.com/h2o/picohttpparser/blob/2a16b2365ba30b13c218d15ed9991576358a6337/picohttpparser.c#L278

This seems non-conforming to rfc7230, what is the rationale?

Start in picohttpparser.c at parse_http_version and parse_headers around the linked line. Compare their handling of HTTP versions and header line endings with the relevant RFC7230 requirements, then determine whether the behavior is intentional. Done means the rationale or required correction is clearly established and covered by an appropriate project test or documentation update.

Written by the indexing model from the issue text.