ignore uninitialized submodules when checking if ./configure should be re-run
Add links to forums in README.md, including discuss.rust-lang.org
Fix snapshot.py for win64
Fix naming of windows installer
Implement tuple and tuple struct indexing

This allows code to access the fields of tuples and tuple structs:

    let x = (1i, 2i);
    assert_eq!(x.1, 2);

    struct Point(int, int);
    let origin = Point(0, 0);
    assert_eq!(origin.0, 0);
    assert_eq!(origin.1, 0);
Be explicit with rustdoc.

I missed some annotations, and some were in a different style.
librustc: Obsolete the old external crate renaming syntax.

Instead of `extern crate foo = bar`, write `extern crate bar as foo`.
Instead of `extern crate baz = "quux"`, write `extern crate "quux" as
baz`.

Closes #16461.

[breaking-change]
auto merge of #17048 : pcwalton/rust/remove-old-import-renaming-syntax, r=brson

Instead of `extern crate foo = bar`, write `extern crate bar as foo`.
Instead of `extern crate baz = "quux"`, write `extern crate "quux" as
baz`.

Closes #16461.

[breaking-change]

r? @brson
Don't ICE on macros with -Z show-span

Closes #17115
auto merge of #17108 : steveklabnik/rust/explicitness, r=alexcrichton

I missed some annotations, and some were in a different style.
micro-optimize dynamic allocation alignment

Previously, some parts of this optimization were impossible because the
alignment passed to the free function was not correct. That was fully
fixed by #17012.

Closes #17092
implement sized deallocation

Closes #13994
auto merge of #17095 : thestinger/rust/alloc, r=alexcrichton

Previously, some parts of this optimization were impossible because the
alignment passed to the free function was not correct. That was fully
fixed by #17012.

Closes #17092
auto merge of #17109 : brson/rust/win64snap, r=alexcrichton
auto merge of #17129 : epdtry/rust/misc/llvm-root-reconfig, r=brson

Currently `./configure --llvm-root=...` and similar flags will break incremental builds by forcing reconfiguration on every `make`.  This happens because `reconfig.mk` incorrectly treats submodules in the `-` (uninitialized) state as requiring reconfiguration, and `./configure` deliberately deinitializes unneeded submodules.  The fix is to reconfigure only when submodules are in the `+` state (wrong commit checked out).
auto merge of #16680 : brson/rust/readme, r=steveklabnik

This adds links to SO, reddit, and discuss to the README. The main intent is to start advertising discuss.rust-lang.org more, in a location that doesn't mislead casual users to it (people who are building Rust are more likely to be the right audience than those that are just visiting the web site).
auto merge of #17135 : brson/rust/wininst, r=alexcrichton

This builds on https://github.com/rust-lang/rust/pull/17109, putting the target triple into the installer name so that we can have both 32-bit and 64-bit.

The resulting installers will be called `rust-0.12.0-pre-x86_64-w64-mingw32.exe`, etc.
auto merge of #16866 : P1start/rust/tuple-indexing, r=brson

This allows code to access the fields of tuples and tuple structs behind the feature gate `tuple_indexing`:

```rust
#![feature(tuple_indexing)]

let x = (1i, 2i);
assert_eq!(x.1, 2);

struct Point(int, int);
let origin = Point(0, 0);
assert_eq!(origin.0, 0);
assert_eq!(origin.1, 0);
```

Implements [RFC 53](https://github.com/rust-lang/rfcs/blob/master/active/0053-tuple-accessors.md). Closes #16950.
auto merge of #17142 : sfackler/rust/issue-17115, r=alexcrichton

Closes #17115
Fix bug in padding unicode, #17105.