Fix some warnings in net.

components/net/lib.rs

@@ -5,10 +5,12 @@
 #![feature(box_syntax)]
 #![feature(collections)]
 #![feature(core)]
-#![feature(env)]
 #![feature(int_uint)]
 #![feature(io)]
+#![feature(old_io)]
+#![feature(old_path)]
 #![feature(path)]
+#![feature(path_ext)]
 #![feature(plugin)]
 #![feature(rustc_private)]
 #![feature(std_misc)]

components/net/sniffer_task.rs

@@ -14,7 +14,7 @@ pub fn new_sniffer_task() -> SnifferTask {
     let builder = Builder::new().name("SnifferManager".to_string());
     builder.spawn(move || {
         SnifferManager::new(rec).start();
-    });
+    }).unwrap();
     sen
 }