Upgrade zstd, zstd-safe, zstd-sys + remove zstd-legacy-mononoke

Summary:
Update these crates since I want some new features, and remove zstd-legacy-mononoke since it's no longer needed.

Notable changes for existing users of zstd_safe:

* `ZSTD_getFrameContentSize` is now provided by [`zstd_safe::get_frame_content_size`](https://docs.rs/zstd-safe/7.0.0/zstd_safe/fn.get_frame_content_size.html)
* `zstd_safe::get_frame_content_size` returns a `Result<Option<u64>>` instead of some special hardcoded numbers (logic is the same though)
* `ZSTD_DStreamOutSize` is now provided by [`zstd_safe::DStream::out_size`](https://docs.rs/zstd-safe/7.0.0/zstd_safe/type.DStream.html#method.out_size)

Reviewed By: markbt

Differential Revision: D50394320

fbshipit-source-id: 3238ec179bef7bc6659506d97b870e0acdb5e86a

shed/async_compression/Cargo.toml

@@ -16,7 +16,7 @@ bzip2 = { version = "0.3", features = ["tokio"] }
 flate2 = { version = "1.0.26", features = ["rust_backend"], default-features = false }
 futures = "0.1.31"
 tokio-io = "0.1"
-zstd = { version = "0.11.2+zstd.1.5.2", features = ["experimental", "zstdmt"] }
+zstd = { version = "0.13", features = ["experimental", "zstdmt"] }
 
 [dev-dependencies]
 assert_matches = "1.5"

shed/chrome_trace/Cargo.toml

@@ -17,7 +17,7 @@ flate2 = { version = "1.0.26", features = ["rust_backend"], default-features = f
 libc = "0.2.139"
 serde = { version = "1.0.185", features = ["derive", "rc"] }
 serde_json = { version = "1.0.100", features = ["float_roundtrip", "unbounded_depth"] }
-zstd = { version = "0.11.2+zstd.1.5.2", features = ["experimental", "zstdmt"] }
+zstd = { version = "0.13", features = ["experimental", "zstdmt"] }
 
 [dev-dependencies]
 maplit = "1.0"