Auto merge of #7097 - boghison:memtypes, r=jdm

Measure heap memory usage for more types. Fixes #6951

Also adds HeapSizeOf implementations/derive for some types. I've used "Cannot calculate Heap size" as a reason everywhere, because my imagination is rather limited. If you'd like me to change this message for specific types, please write something like this: "Trusted - Cannot calculate Heap size for Trusted" so that it would be easier for me to replace them through a script :)

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components/script/lib.rs

@@ -66,6 +66,7 @@ extern crate profile_traits;
 extern crate script_traits;
 extern crate selectors;
 extern crate smallvec;
+#[macro_use]
 extern crate util;
 extern crate websocket;
 #[macro_use]