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> {
```

components/script/dom/bindings/conversions.rs

@@ -272,9 +272,8 @@ pub fn jsstring_to_str(cx: *mut JSContext, s: *mut JSString) -> DOMString {
     unsafe {
         let mut length = 0;
         let chars = JS_GetStringCharsAndLength(cx, s, &mut length);
-        slice::raw::buf_as_slice(chars, length as uint, |char_vec| {
-            String::from_utf16(char_vec).unwrap()
-        })
+        let char_vec = slice::from_raw_buf(&chars, length as uint);
+        String::from_utf16(char_vec).unwrap()
     }
 }
 
@@ -328,14 +327,14 @@ impl FromJSValConvertible<()> for ByteString {
 
             let mut length = 0;
             let chars = JS_GetStringCharsAndLength(cx, string, &mut length);
-            slice::raw::buf_as_slice(chars, length as uint, |char_vec| {
-                if char_vec.iter().any(|&c| c > 0xFF) {
-                    // XXX Throw
-                    Err(())
-                } else {
-                    Ok(ByteString::new(char_vec.iter().map(|&c| c as u8).collect()))
-                }
-            })
+            let char_vec = slice::from_raw_buf(&chars, length as uint);
+
+            if char_vec.iter().any(|&c| c > 0xFF) {
+                // XXX Throw
+                Err(())
+            } else {
+                Ok(ByteString::new(char_vec.iter().map(|&c| c as u8).collect()))
+            }
         }
     }
 }

components/script/dom/bindings/js.rs

@@ -51,7 +51,7 @@ use dom::node::Node;
 use js::jsapi::JSObject;
 use js::jsval::JSVal;
 use layout_interface::TrustedNodeAddress;
-use script_task::StackRoots;
+use script_task::STACK_ROOTS;
 
 use servo_util::smallvec::{SmallVec, SmallVec16};
 use std::cell::{Cell, UnsafeCell};
@@ -101,7 +101,7 @@ impl<T: Reflectable> Temporary<T> {
 
     /// Create a stack-bounded root for this value.
     pub fn root(self) -> Root<T> {
-        StackRoots.with(|ref collection| {
+        STACK_ROOTS.with(|ref collection| {
             let RootCollectionPtr(collection) = collection.get().unwrap();
             unsafe {
                 Root::new(&*collection, &self.inner)
@@ -164,7 +164,7 @@ impl<T: Reflectable> JS<T> {
 
     /// Root this JS-owned value to prevent its collection as garbage.
     pub fn root(&self) -> Root<T> {
-        StackRoots.with(|ref collection| {
+        STACK_ROOTS.with(|ref collection| {
             let RootCollectionPtr(collection) = collection.get().unwrap();
             unsafe {
                 Root::new(&*collection, self)

components/script/dom/bindings/refcounted.rs

@@ -36,7 +36,7 @@ use std::collections::hash_map::{HashMap, Vacant, Occupied};
 use std::rc::Rc;
 use std::sync::{Arc, Mutex};
 
-thread_local!(pub static LiveReferences: Rc<RefCell<Option<LiveDOMReferences>>> = Rc::new(RefCell::new(None)))
+thread_local!(pub static LIVE_REFERENCES: Rc<RefCell<Option<LiveDOMReferences>>> = Rc::new(RefCell::new(None)))
 
 
 /// A safe wrapper around a raw pointer to a DOM object that can be
@@ -57,7 +57,7 @@ impl<T: Reflectable> Trusted<T> {
     /// be prevented from being GCed for the duration of the resulting `Trusted<T>` object's
     /// lifetime.
     pub fn new(cx: *mut JSContext, ptr: JSRef<T>, script_chan: Box<ScriptChan + Send>) -> Trusted<T> {
-        LiveReferences.with(|ref r| {
+        LIVE_REFERENCES.with(|ref r| {
             let r = r.borrow();
             let live_references = r.as_ref().unwrap();
             let refcount = live_references.addref(cx, &*ptr as *const T);
@@ -74,7 +74,7 @@ impl<T: Reflectable> Trusted<T> {
     /// a different thread than the original value from which this `Trusted<T>` was
     /// obtained.
     pub fn to_temporary(&self) -> Temporary<T> {
-        assert!(LiveReferences.with(|ref r| {
+        assert!(LIVE_REFERENCES.with(|ref r| {
             let r = r.borrow();
             let live_references = r.as_ref().unwrap();
             self.owner_thread == (&*live_references) as *const _ as *const libc::c_void
@@ -123,7 +123,7 @@ pub struct LiveDOMReferences {
 impl LiveDOMReferences {
     /// Set up the task-local data required for storing the outstanding DOM references.
     pub fn initialize() {
-        LiveReferences.with(|ref r| {
+        LIVE_REFERENCES.with(|ref r| {
             *r.borrow_mut() = Some(LiveDOMReferences {
                 table: RefCell::new(HashMap::new()),
             })
@@ -152,7 +152,7 @@ impl LiveDOMReferences {
 
     /// Unpin the given DOM object if its refcount is 0.
     pub fn cleanup(cx: *mut JSContext, raw_reflectable: *const libc::c_void) {
-        LiveReferences.with(|ref r| {
+        LIVE_REFERENCES.with(|ref r| {
             let r = r.borrow();
             let live_references = r.as_ref().unwrap();
             let reflectable = raw_reflectable as *const Reflector;