Improve naming of tuple getters, and add mutable tuple getter

Renames the `n*` and `n*_ref` tuple getters to `val*` and `ref*` respectively, and adds `mut*` getters.

src/libcollections/btree.rs

@@ -500,15 +500,15 @@ impl<K: Clone + TotalOrd, V: Clone> Branch<K, V> {
                     let new_outcome = self.clone().rightmost_child.insert(k.clone(),
                                                                        v.clone(),
                                                                        ub.clone());
-                    new_branch = new_outcome.clone().n0();
-                    outcome = new_outcome.n1();
+                    new_branch = new_outcome.clone().val0();
+                    outcome = new_outcome.val1();
                 }
                 else {
                     let new_outcome = self.clone().elts[index.unwrap()].left.insert(k.clone(),
                                                                                  v.clone(),
                                                                                  ub.clone());
-                    new_branch = new_outcome.clone().n0();
-                    outcome = new_outcome.n1();
+                    new_branch = new_outcome.clone().val0();
+                    outcome = new_outcome.val1();
                 }
                 //Check to see whether a branch or a leaf was returned from the
                 //tree traversal.

src/librustdoc/html/render.rs

@@ -1379,11 +1379,11 @@ fn render_methods(w: &mut Writer, it: &clean::Item) -> fmt::Result {
         match c.impls.find(&it.id) {
             Some(v) => {
                 let mut non_trait = v.iter().filter(|p| {
-                    p.n0_ref().trait_.is_none()
+                    p.ref0().trait_.is_none()
                 });
                 let non_trait = non_trait.to_owned_vec();
                 let mut traits = v.iter().filter(|p| {
-                    p.n0_ref().trait_.is_some()
+                    p.ref0().trait_.is_some()
                 });
                 let traits = traits.to_owned_vec();
 

src/librustdoc/lib.rs

@@ -262,7 +262,7 @@ fn rust_input(cratefile: &str, matches: &getopts::Matches) -> Output {
     let mut pm = plugins::PluginManager::new(Path::new(path));
     for pass in passes.iter() {
         let plugin = match PASSES.iter().position(|&(p, _, _)| p == *pass) {
-            Some(i) => PASSES[i].n1(),
+            Some(i) => PASSES[i].val1(),
             None => {
                 error!("unknown pass {}, skipping", *pass);
                 continue