Simultaneous futures compat (#172)

This patch adds opt-in support for futures 0.2.

futures2/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "futures2"
+
+version = "0.1.0"
+authors = ["Aaron Turon <[email protected]>"]
+license = "MIT/Apache-2.0"
+repository = "https://github.com/tokio-rs/tokio"
+homepage = "https://tokio.rs"
+
+[dependencies]
+futures = "0.2.0-alpha"

futures2/src/lib.rs

@@ -0,0 +1,2 @@
+extern crate futures;
+pub use futures::*;