Update to rust master

rust-lang/rust#19253 and rust-lang/rust@25f8051 have introduced changes
to the namespacing within the std::collections::hash_map, breaking some
of Cargo code which imported these.

rust-lang/rust@cf350ea, implementing changes proposed by RFC rust-lang#344, have
also broken some code which relies on hash_set::SetItems (now renamed to
hash_set::Iter).

This commit fixes the incompatibilities: imports of
std::collections::hash_map::{Occupied, Vacant} have been replaced by
imports of std::collections::hash_map::Entry::{Occupied, Vacant} and one
instance where the SetItems has been used was replaced by the proper
usage of Iter.

src/cargo/core/registry.rs

@@ -1,5 +1,6 @@
 use std::collections::HashSet;
-use std::collections::hash_map::{HashMap, Occupied, Vacant};
+use std::collections::hash_map::HashMap;
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 
 use core::{Source, SourceId, SourceMap, Summary, Dependency, PackageId, Package};
 use util::{CargoResult, ChainError, Config, human, profile};

src/cargo/core/resolver/mod.rs

@@ -1,6 +1,7 @@
 use std::cell::RefCell;
 use std::collections::HashSet;
-use std::collections::hash_map::{HashMap, Occupied, Vacant};
+use std::collections::hash_map::HashMap;
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::fmt;
 use std::rc::Rc;
 use semver;

src/cargo/ops/cargo_rustc/context.rs

@@ -1,4 +1,5 @@
-use std::collections::hash_map::{HashMap, Occupied, Vacant};
+use std::collections::hash_map::HashMap;
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::str;
 use std::sync::Arc;
 

src/cargo/ops/cargo_rustc/fingerprint.rs

@@ -1,4 +1,4 @@
-use std::collections::hash_map::{Occupied, Vacant};
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::hash::{Hash, Hasher};
 use std::hash::sip::SipHasher;
 use std::io::{mod, fs, File, BufferedReader};

src/cargo/ops/cargo_rustc/job_queue.rs

@@ -1,5 +1,6 @@
 use std::collections::HashSet;
-use std::collections::hash_map::{HashMap, Occupied, Vacant};
+use std::collections::hash_map::HashMap;
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::sync::TaskPool;
 use term::color::YELLOW;
 

src/cargo/util/config.rs

@@ -1,6 +1,7 @@
 use std::{fmt, os, mem};
 use std::cell::{RefCell, RefMut};
-use std::collections::hash_map::{HashMap, Occupied, Vacant};
+use std::collections::hash_map::{HashMap};
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::io;
 use std::io::fs::{mod, PathExtensions, File};
 use std::string;

src/cargo/util/dependency_queue.rs

@@ -4,8 +4,9 @@
 //! This structure is used to store the dependency graph and dynamically update
 //! it to figure out when a dependency should be built.
 
-use std::collections::{HashMap, HashSet};
-use std::collections::hash_map::{Occupied, Vacant};
+use std::collections::hash_set::HashSet;
+use std::collections::hash_map::HashMap;
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::hash::Hash;
 
 pub use self::Freshness::{Fresh, Dirty};

src/cargo/util/graph.rs

@@ -1,8 +1,9 @@
 use std::fmt;
 use std::hash::Hash;
-use std::collections::{HashMap, HashSet};
-use std::collections::hash_map::{Keys, Occupied, Vacant};
-use std::collections::hash_set::SetItems;
+use std::collections::hash_set::HashSet;
+use std::collections::hash_map::{HashMap, Keys};
+use std::collections::hash_map::Entry::{Occupied, Vacant};
+use std::collections::hash_set::Iter;
 
 pub struct Graph<N> {
     nodes: HashMap<N, HashSet<N>>
@@ -14,7 +15,7 @@ enum Mark {
 }
 
 pub type Nodes<'a, N> = Keys<'a, N, HashSet<N>>;
-pub type Edges<'a, N> = SetItems<'a, N>;
+pub type Edges<'a, N> = Iter<'a, N>;
 
 impl<N: Eq + Hash + Clone> Graph<N> {
     pub fn new() -> Graph<N> {