Update to current rust: don't use libextra.

Ms2ger · Ms2ger · commit 131b8e733802 · 2014-03-21T22:53:53.000+01:00
diff --git a/lib.rs b/lib.rs
@@ -5,7 +5,6 @@
 #[crate_id = "github.com/mozilla-servo/rust-cssparser#cssparser:0.1"];
 #[feature(globs, macro_rules)];
 
-extern crate extra;
 extern crate encoding;  // https://github.com/lifthrasiir/rust-encoding
 
 #[cfg(test)]
