auto merge of #4575 : mttr/servo/warnings, r=jdm

Notes:

* This adds `#![allow(missing_copy_implementations)]` to components/*/lib.rs. I'm not sure how to approach the missing Copy warnings (are there things for which Copy should NOT be implemented, and how can I tell?) so I stuck this in to make life easier when looking through the warnings. I can easily remove this if necessary. 
* This leaves the following type of warnings, which I couldn't figure out how to approach (I'll investigate it later if no one else wants to).
```
css/matching.rs:72:23: 72:35 warning: use of deprecated item: Use overloaded core::cmp::PartialEq, #[warn(deprecated)] on by default
css/matching.rs:72         this_as_query.equiv(other)
                                         ^~~~~~~~~~~~
css/matching.rs:95:10: 95:49 warning: use of deprecated item: Use overloaded core::cmp::PartialEq, #[warn(deprecated)] on by default
css/matching.rs:95 impl<'a> Equiv<ApplicableDeclarationsCacheEntry> for ApplicableDeclarationsCacheQuery<'a> {
```

1 files changed, 2 insertions, 2 deletions

diff --git a/components/script/dom/formdata.rs b/components/script/dom/formdata.rs
index 42a495686ed..bcac91da97e 100644
--- a/components/script/dom/formdata.rs
+++ b/components/script/dom/formdata.rs
@@ -81,7 +81,7 @@ impl<'a> FormDataMethods for JSRef<'a, FormData> {
     }
 
     fn Get(self, name: DOMString) -> Option<FileOrString> {
-        if self.data.borrow().contains_key_equiv(&name) {
+        if self.data.borrow().contains_key(&name) {
             match (*self.data.borrow())[name][0].clone() {
                 FormDatum::StringData(ref s) => Some(eString(s.clone())),
                 FormDatum::FileData(ref f) => {
@@ -94,7 +94,7 @@ impl<'a> FormDataMethods for JSRef<'a, FormData> {
     }
 
     fn Has(self, name: DOMString) -> bool {
-        self.data.borrow().contains_key_equiv(&name)
+        self.data.borrow().contains_key(&name)
     }
     #[allow(unrooted_must_root)]
     fn Set(self, name: DOMString, value: JSRef<Blob>, filename: Option<DOMString>) {