linux: reduce file descriptor count of async pipe

Reopen one of the pipe descriptors as read/write through the procfs.
Allows us to close the original pipe file descriptors, saving a file
descriptor on kernels that don't support eventfd(2).
sunos: support IPv6 qualified link-local addresses
windows: fix opening of read-only stdin pipes

Fix https://github.com/joyent/node/issues/7345

Google Chrome is launching native messaging hosts by invoking cmd.exe
with input/output redirected from/to named pipes. The host ends up
with a read-only handle to the stdin pipe. This is causing
SetNamedPipeHandleState to fail.
build: fix building with old versions of autoconf
windows: Fix an infinite loop in uv_spawn

The PATH-parsing code for windows erroneously contained an infinite
loop when the PATH started with a leading semicolon. Each iteration of
the loop usually bumped over the separator, but if the first character
was a semicolon then it would never skip it, causing the infinite
loop.

Closes #909
test: Close process handles when spawn fails

This should avoid assertions tripping in debug mode.
windows: fix console signal handler refcount
test: fix EPIPE race in spawn_closed_process_io

The just created stdin should not be closed by a child process before
writing to it, otherwise EPIPE happens.
windows: fix console signal handler refcount

Backport of 0c726e7 from master
inet: allow scope in `uv_inet_pton` ip6 check

Note that isn't actually parsing it, since the output value is a
`struct in6_addr`.

see https://github.com/joyent/node/issues/7395
Revert "inet: allow scope in `uv_inet_pton` ip6 check"

This reverts commit d30e3ab65acf7b77945658d3e6127ca6af6eec6, because it
is a new feature!
inet: allow scopeid in uv_inet_pton

We already support it in `uv_ip6_addr` anyway.

See https://github.com/joyent/node/issues/7395
include: add reserved field for #926

Introduce reserved field to be able to fix #926 after v0.12 release.
win: always leave crit section in get_proc_title

fix #1235
Merge branch 'v0.10'

Conflicts:
	src/win/signal.c
	src/win/util.c
2014.04.15, Version 0.11.24 (Unstable)

Changes since version 0.11.23:

* linux: reduce file descriptor count of async pipe (Ben Noordhuis)

* sunos: support IPv6 qualified link-local addresses (Saúl Ibarra
  Corretgé)

* windows: fix opening of read-only stdin pipes (Alexis Campailla)

* windows: Fix an infinite loop in uv_spawn (Alex Crichton)

* windows: fix console signal handler refcount (李港平)

* inet: allow scopeid in uv_inet_pton (Fedor Indutny)

* win: always leave crit section in get_proc_title (Fedor Indutny)
Now working on v0.11.25
include: reorder UV_HANDLE_PRIVATE_FIELDS

The fields for UV_HANDLE_PRIVATE_FIELDS in uv-win.h and uv-unix.h are
the same, but in different order. Simply swap them so uv_handle_t are
the same on both platforms.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
test: fix compilation warnings with VC++

C6011 and C4244
authors: fix name