Merge pull request #7 from rust-lang-nursery/ndm-release-0.9.0

bump to 0.9.0 and update README

Author: nikomatsakis

Cargo.toml

@@ -4,7 +4,7 @@ description = "Union-find, congruence closure, and other unification code. Based
 license = "MIT/Apache-2.0"
 homepage = "https://github.com/nikomatsakis/ena"
 repository = "https://github.com/nikomatsakis/ena"
-version = "0.8.0"
+version = "0.9.0"
 authors = ["Niko Matsakis <niko@alum.mit.edu>"]
 readme = "README.md"
 keywords = ["unification", "union-find"]

README.md

@@ -1,24 +1,18 @@
 [![Build Status](https://travis-ci.org/nikomatsakis/ena.svg?branch=master)](https://travis-ci.org/nikomatsakis/ena)
 
-An implementation of union-find / congruence-closure in Rust. Forked
-from rustc for independent experimentation. My intention is to iterate
-and improve this code and gradually bring back changes into rustc
-itself, but also to enable other crates.io packages to use the same
-code.
+An implementation of union-find in Rust; extracted from (and used by)
+rustc.
 
 ### Name
 
 The name "ena" comes from the Greek word for "one".
 
 ### Features
 
-By default, you just get the union-find implementation. You can
-also opt-in to the following experimental features:
+By default, you just get the union-find implementation. You can also
+opt-in to the following experimental features:
 
 - `bench`: use to run benchmarks (`cargo bench --features bench`)
-- `congruence-closure`: opt-in to the congruence closure
-  implementation. This requires petgraph and is nightly only (since
-  it uses `impl Trait`).
 
 ### License