Sort: Implement stable sort, ignore non-printing, month sort dedup, auto parallel sort through rayon, zero terminated sort, check silent

src/uu/sort/Cargo.toml

@@ -15,9 +15,10 @@ edition = "2018"
 path = "src/sort.rs"
 
 [dependencies]
+rayon = "1.5"
 rand = "0.7"
 clap = "2.33"
-twox-hash = "1.6.0"
+fnv = "1.0.7"
 itertools = "0.8.0"
 semver = "0.9.0"
 uucore = { version=">=0.0.8", package="uucore", path="../../uucore", features=["fs"] }