v1.5.4
AsyncIO compression part 1 - refactor of existing asyncio code (#3021)
Coalesce Almost All Copyright Notices to Standard Phrasing
Spelling (#1582)
Rename "External Matchfinder" to "Block-Level Sequence Producer" (#3484)
minor: fix missing newline character in help page
Delete unused Huffman functions
Fix wrong conditions
fix 32bit build errors in zstd seekable
moved snap to /contrib
created contrib/cleanTabs