unix, windows: don't include null byte in uv_cwd size

Make it consistent with uv_exepath
unix, windows: add uv_thread_equal
windows: fix fs_write with nbufs > 1 and offset

When multiple bufs are specified, overlapped needs to be advanced
manually between each write.  Without this, each buf will be written
to the same position (if offset is specified.)

ReadFile() automatically advances, but WriteFile() does not.
2014.10.21, Version 1.0.0-rc2 (Pre-release)

Changes since version 1.0.0-rc1:

* build: add missing fixtures to distribution tarball (Rob Adams)

* doc: update references to current stable branch (Zachary Newman)

* fs: fix readdir on empty directory (Fedor Indutny)

* fs: rename uv_fs_readdir to uv_fs_scandir (Saúl Ibarra Corretgé)

* doc: document uv_alloc_cb (Saúl Ibarra Corretgé)

* doc: add migration guide from version 0.10 (Saúl Ibarra Corretgé)

* build: add DragonFly BSD support in autotools (Robin Hahling)

* doc: document missing stream related structures (Saúl Ibarra Corretgé)

* doc: clarify uv_loop_t.data field lifetime (Saúl Ibarra Corretgé)

* doc: add documentation for missing functions and structures (Saúl
  Ibarra Corretgé)

* doc: fix punctuation and grammar in README (Jeff Widman)

* windows: return libuv error codes in uv_poll_init() (cjihrig)

* unix, windows: add uv_fs_access() (cjihrig)

* windows: fix netmask detection (Alexis Campailla)

* unix, windows: don't include null byte in uv_cwd size (Saúl Ibarra
  Corretgé)

* unix, windows: add uv_thread_equal (Tomasz Kołodziejski)

* windows: fix fs_write with nbufs > 1 and offset (Unknown W. Brackets)
version: now working on 1.0.0-rc3
doc: fix git/svn url for gyp repo in README
windows: fix fs_read with nbufs > 1 and offset

ReadFile() does not seem to update the offset at all.
build: add x32 support to gyp build

This commit adds x32 support to the gyp build.  Configure with:

    $ ./gyp_uv.py -Dtarget_arch=x32
build: remove dtrace probes

The existing probes, all two of them, cause a great deal of pain for
people trying to build libuv on Linux because of SystemTap's dtrace(1)
utilitity not understanding the -xnolibs flag.

We could hack around that but it's easier to just remove the probes:
they are largely useless and unused while still needing a lot of
supporting infrastructure.  This commit removes 200 lines of code
and configuration.

Refs joyent/libuv#1478.