After a hash mismatch error, emit file-system paths of crates involved.

Fix #13266.

There is a little bit of acrobatics in the definition of `crate_paths`
to avoid calling `clone()` on the dylib/rlib unless we actually are
going to need them.

The other oddity is that I have replaced the `root_ident: Option<&str>`
parameter with a `root: &Option<CratePaths>`, which may surprise one
who was expecting to see something like: `root: Option<&CratePaths>`.
I went with the approach here because I could not come up with code for
the alternative that was acceptable to the borrow checker.
Removed references to managed boxes/pointers from the tutorial text. Code
examples in relevant sections were similarly altered.
Removed all references to managed closures.
std: Document builtin syntax extensions

These syntax extensions need a place to be documented, and this starts passing a
`--cfg dox` parameter to `rustdoc` when building and testing documentation in
order to document macros so that they have no effect on the compiled crate, but
only documentation.

Closes #5605
Bump version to 0.11-pre

This also changes some of the download links in the documentation
to 'nightly'.
Add fetch_and, fetch_or, fetch_xor to AtomicInt, AtomicUint
stop asking LLVM to null-terminate strings

This was missed when dropping the null-termination from our string
types. An explicit null byte can still be placed anywhere in a string if
desired, but there's no reason to stick one at the end of every string
constant.
auto merge of #13296 : brson/rust/0.11-pre, r=alexcrichton

This also changes some of the download links in the documentation
to 'nightly'.
std: Remove `RefCell::get()`

It's surprising that `RefCell::get()` is implicitly doing a clone
on a value. This patch removes it and replaces all users with
either `.borrow()` when we can autoderef, or `.borrow().clone()`
when we cannot.
std: Remove `RefCell::set()`
test: avoid infinite loop in out-of-stack.rs

This fixes #13238. It avoids an infinite loop when compiling
the tests with `-g`. Without this change, the debuginfo on
`black_box` prevents the method from being inlined, which
allows llvm to convert `silent_recurse` into a tail-call. This
then loops forever instead of consuming all the stack like it
is supposed to. This patch forces inlining `black_box`, which
triggers the right error.
manual: update the note about reserved attributes
manual: many fixes

Mostly around attributes and language items.
etc: attempts at fixing editor highlighting for new attribute syntax
auto merge of #12964 : gereeter/rust/extended-atomics, r=alexcrichton

Fixes #12949.
rustdoc: Fix reporting of ignored tests

librustdoc: instead of skipping ignored tests, pass them to libtest
so it can report them as such.  If a test is marked as `notrust`,
however, it will not show up in the final report.
manual: update style
manual: fix attribute ebnf
manual: further attribute clarifications

- Sort attributes lexicographically
- Use new attribute syntax consistently
- Fix wording describing new attribute syntax
- Expand section on `repr`
manual: refine ECMA-335 reference for attributes