Makes cross-building (e.g. to linux-musl) substantially easier. * [x] `lz4` -> [`lz-fear`](https://github.com/main--/rust-lz-fear): apparently performance parity * [ ] `zstd` -> [`ruzstd`](https://github.com/KillingSpark/zstd-rs): apparently ~3.5x slower, no encoding
