v1.2.1: Merge pull request #74 from klauspost/reduce_stack_impact_issue_18625

Reduce stack pressure due to array copies

v1.2: Merge pull request #67 from klauspost/finetune-level2-4

Fine tune level 2-4

v1.1

Update README.md

v1.0: Merge pull request #46 from rasky/patch-1

Clarify that snappy is still gzip compatible