• [API] Use lsxpack_header structure to process incoming headers.
• [BUGFIX] Fix assertion when zero-padding Initial packet.
• [BUGFIX] Use idle timeout before we learn of peer's value.
• Use ls-hpack 2.0.0 -- has lsxpack_header changes.
• Use ls-qpack 0.14.0 -- new, common with ls-hpack, XXH seed (not used yet).
• Code cleanup: prefix exported functions with "lsquic_".