servo: Merge #4756 - Fix various build warnings (from Ms2ger:warnings); r=mbrubeck

Source-Repo: https://github.com/servo/servo
Source-Revision: 88b781421aa78a2f466e6d170f89d13a870643cd

servo/components/script_traits/lib.rs

@@ -7,6 +7,7 @@
 #![deny(unused_imports)]
 #![deny(unused_variables)]
 #![allow(missing_copy_implementations)]
+#![allow(unstable)]
 
 extern crate devtools_traits;
 extern crate geom;