Don't make tags for our dependencies and tests.

Largely, this is just being more specific about where tags get searched
for to remove external dependencies like src/llvm, which reduces the
number of tags *enormously* and significantly increases the usefulness
of the tags file as it is then focusing on 240K lines of Rust code
and 4.5K of C++ rather than just shy of 1M lines of C++ code (mostly
from LLVM) and another 100K lines of Rust tests and a diverse collection
of other languages.

src/rustllvm/RustWrapper.cpp and src/rustllvm/PassWrapper.cpp are
getting tags made, but I'm not sure if that's desirable or not. At
worst, it's not a significant wrong.

A future, desirable step is producing tags for just libstd and libextra
for the use of people using Rust-the-language rather than working on
Rust itself.
fix 10468, propagate optimization level as rustc::driver::session::OptLevel
resurect shootout-mandelbrot.rs

Changes:
* add licence;
* remove usage of libc and unsafe;
* use BufferedWriter to improve performance;
* use a DummyWriter to cancel binary output in test.
Clarrify the message for test mode and use u8 instead of i8 for storing bits
Prettier long string breaking.
Add doc comment for extra::url::query_to_str
auto merge of #10531 : TeXitoi/rust/mandelbrot-resurected, r=cmr

Changes:
* add licence;
* remove usage of libc and unsafe;
* use BufferedWriter to improve performance;
* use a DummyWriter to cancel binary output in test.
auto merge of #10532 : dhodder/rust/master, r=alexcrichton

Hello.  This is just a tiny doc update -- I'm new here, so apologies if I'm doing it wrong.
Add a test for #6976

Closes #6976
Better error message when using vectors in statics

Closes #10487
auto merge of #10511 : cmr/rust/addtests, r=huonw

Commit messages have all
Fixed uses of get() to unwrap() in doc examples in std::iter
Fixed docs for advance() in Iterator trait
auto merge of #10533 : tautologico/rust/fixdocs, r=huonw

This fixes a number of bugs in the doc comments for a bunch of functions in libstd/iter.rs, mostly updating to use unwrap() instead of get() on options. Also fixes the docs for advance() (trait Iterator) which was not making sense, though if it is not useful anymore maybe it should be removed.
Fix XFailed test x86stdcall

There was a syntax error because the `extern "stdcall"` was outside the module instead of inside it.

* moved `extern` inside module
* change `extern "stdcall"` to `extern "system"`
* change `cfg(target_os="win32")` to `cfg(windows)`
* updated copyright dates
* changed log(error, ...) => info!(....)
* added `pub` keyword to kernel32 functions
auto merge of #10363 : astrieanna/rust/fix-x86stdcall, r=huonw

* moved `extern` inside module
* changed `extern "stdcall"` to `extern "system"`
* changed `cfg(target_os="win32")` to `cfg(windows)`
* only run on Windows && x86, (not x86_64)
* updated copyright dates
auto merge of #10526 : itdaniher/rust/master, r=pcwalton

This commit fixes issue #10468.

It propagate optimization level from PkgSrc to compile_crate as a rustc::driver::session::OptLevel enum.

The 'opt' argument to compile_crate was previously hardcoded as boolean false, such that calls to session::options would always result in the session::No flag being used.
Forbid privacy in inner functions

Closes #10111
auto merge of #10443 : alexcrichton/rust/meaninless-pub-priv, r=cmr

Closes #10111
auto merge of #10508 : chris-morgan/rust/tags-improvements, r=cmr

Largely, this is just being more specific about where tags get searched
for to remove external dependencies like src/llvm, which reduces the
number of tags *enormously* and significantly increases the usefulness
of the tags file as it is then focusing on 240K lines of Rust code
and 4.5K of C++ rather than just shy of 1M lines of C++ code (mostly
from LLVM) and another 100K lines of Rust tests and a diverse collection
of other languages.

src/rustllvm/RustWrapper.cpp and src/rustllvm/PassWrapper.cpp are
getting tags made, but I'm not sure if that's desirable or not. At
worst, it's not a significant wrong.

A future, desirable step is producing tags for just libstd and libextra
for the use of people using Rust-the-language rather than working on
Rust itself.