Remove Real trait and move methods into Float

This is part of the effort to simplify `std::num`, as tracked in issue #10387.
Minor documentation fixes in std::fmt

* Change '...your own time' => '...your own type'
* Fix typo in the Vector2D example
Clean up std::task docs, make TaskBuilder a real builder

Delete all the documentation from std::task that references linked
failure.

Tweak TaskBuilder to be more builder-like. .name() is now .named() and
.add_wrapper() is now .with_wrapper(). Remove .watched() and
.unwatched() as they didn't actually do anything.
Update clients of the TaskBuilder API
Implement Unix domain sockets in libnative
Move unix pipes implementation to pipe_unix.rs

The windows named pipes implementation will have almost nothing to do with unix
pipes, so I think it's best if they live in separate files.
Implement named pipes for windows, touch up unix

* Implementation of pipe_win32 filled out for libnative
* Reorganize pipes to be clone-able
* Fix a few file descriptor leaks on error
* Factor out some common code into shared functions
* Make use of the if_ok!() macro for less indentation

Closes #11201
Rename Bitwise::population_count to Bitwise::count_ones and add Bitwise::count_zeros

These are inspired by the [functions in the Julia standard library](http://docs.julialang.org/en/release-0.2/stdlib/base/#Base.count_ones).
Forbid use of generics with foreign functions. Closes #10353.
auto merge of #12325 : big-guy/rust/doc-fixes, r=alexcrichton

* Change '...your own time' => '...your own type'
* Fix typo in the Vector2D example
auto merge of #12331 : bjz/rust/count-ones, r=alexcrichton

This is inspired by the [function naming in the Julia standard library](http://docs.julialang.org/en/release-0.2/stdlib/base/#Base.count_ones). It seems like a more self-explanatory name, and is more consistent with the accompanying methods, `leading_zeros` and `trailing_zeros`.
Added more scripts to tidy check
auto merge of #12337 : nick29581/rust/generic_extern, r=alexcrichton

and fix up some formatting.
Fix a deadlock in channels, again.

This deadlock was caused when the channel was closed at just the right time, so
the extra `self.cnt.fetch_add` actually should have preserved the DISCONNECTED
state of the channel. by modifying this the channel entered a state such that
the port would never succeed in dropping.

This also moves the increment of self.steals until after the MAX_STEALS block.
The reason for this is that in 'fn recv()' the steals variable is decremented
immediately after the try_recv(), which could in theory set steals to -1 if it
was previously set to 0 in try_recv().

Closes #12340
auto merge of #12352 : alexcrichton/rust/fix-master, r=brson

This deadlock was caused when the channel was closed at just the right time, so
the extra `self.cnt.fetch_add` actually should have preserved the DISCONNECTED
state of the channel. by modifying this the channel entered a state such that
the port would never succeed in dropping.

This also moves the increment of self.steals until after the MAX_STEALS block.
The reason for this is that in 'fn recv()' the steals variable is decremented
immediately after the try_recv(), which could in theory set steals to -1 if it
was previously set to 0 in try_recv().

Closes #12340
Updated metadata::creader::resolve_crate_deps to use the correct span. Clarified error message when an external crate's dependency is missing. Closes #2404.
auto merge of #12146 : gentlefolk/rust/issue-2404, r=alexcrichton

Addresses FIXME described in issue #2404
auto merge of #12232 : kballard/rust/taskbuilder-is-a-builder, r=alexcrichton

Delete all the documentation from std::task that references linked
failure.

Tweak TaskBuilder to be more builder-like. `.name()` is now `.named()` and
`.add_wrapper()` is now `.with_wrapper()`. Remove `.watched()` and
`.unwatched()` as they didn't actually do anything.

Closes #6399.
auto merge of #12243 : dguenther/rust/extend-tidy, r=alexcrichton

Extends the license and formatting check to `*.js` files in `src/doc` and `*.sh`, `*.pl`, `*.c`, and `*.h` files in `src/etc`. As best as I could tell, these files should be covered under the Rust project license.

cc @brson: Do any other scripts need a license? I'd like to double-check that this PR closes #4534.
auto merge of #12103 : alexcrichton/rust/unix, r=brson

There's a few parts to this PR

* Implement unix pipes in libnative for unix platforms (thanks @Geal!)
* Implement named pipes in libnative for windows (terrible, terrible code)
* Remove `#[cfg(unix)]` from `mod unix` in `std::io::net`. This is a terrible name for what it is, but that's the topic of #12093.

The windows implementation was significantly more complicated than I thought it would be, but it seems to be passing all the tests. now.

Closes #11201