doc: Don't mention TLS in condition tutorial
Change use of unsigned integers to signed integers for clarity in
precise_time_ns

The QueryPerformance* functions take a LARGE_INTEGER, which is a signed
64-bit integer rather than an unsigned 64-bit integer. `ts.tv_sec`, too,
is a signed integer so `ns_per_s` has been changed to a int64_t.
Add asserts to check for faililng QueryPerformance* calls in precise_time_ns
Closes #2675.
auto merge of #10403 : poiru/rust/issue-2675, r=alexcrichton

Closes #2675.
auto merge of #10419 : brson/rust/conditiondocs, r=alexcrichton

Fixes #8553 by just not mentioning TLS, and instead just referring to the 'task-local condition handler'.
auto merge of #10422 : alexcrichton/rust/explicit-crate-map, r=pcwalton

As we start to move runtime components into the crate map, it's becoming harder
and harder to start the runtime from a C function as rust is embedded in another
application. Right now if you compile a rust crate as a dynamic library which is
then linked to another application, when using std::rt::start there are no I/O
local services, even though rustuv was linked against and requested. The reason
for this is that there is no top level crate map available specifying where to
find libuv I/O.

This option is not meant to be used regularly, but rather whenever compiling a
final library crate and linking it into another application. This lifts the
requirement that to get a crate map you must have the final destination be an
executable.
Implemented a ProcessExit enum and helper methods to std::rt::io::process for getting process termination status, or the signal that terminated a process.

A test has been added to rtio-processes.rs to ensure signal termination is picked up correctly.
auto merge of #10109 : pcmattman/rust/pass-nonzero-exit-status-on-termination-by-signal, r=alexcrichton

The UvProcess exit callback is called with a zero exit status and non-zero termination signal when a child is terminated by a signal.

If a parent checks only the exit status (for example, only checks the return value from `wait()`), it may believe the process completed successfully when it actually failed.

Helpers for common use-cases are in `std::rt::io::process`.

Should resolve https://github.com/mozilla/rust/issues/10062.
Move std::rt::io to std::io