unix, windows: always update loop time

Fixes #846
2013.12.13, Version 0.10.20 (Stable)

Changes since version 0.10.19:

* linux: fix up SO_REUSEPORT back-port (Ben Noordhuis)

* fs-event: fix invalid memory access (huxingyi)
Now working on v0.10.21
windows: translate system errors in uv_spawn

We weren't always translating system errors for in uv_spawn.

This is half a fix for node's unit test
 test-child-process-cwd.js on win.
 The rest will go into node lib.
 It also fixes test-child-process-exec-error
windows: uv_spawn code refactor
Merge remote-tracking branch 'origin/v0.10'

Conflicts:
	.mailmap
	ChangeLog
	src/version.c
unix, windows: detect errors in uv_ip4/6_addr
stream: introduce uv_try_write(...)

`uv_try_write(stream, buf, size)` acts like `uv_write()`,
but without queueing actual write until UV_POLLOUT (or IOCP completion).
This is useful for doing writes using on-stack `uv_write_t` requests.

fix #1025
2013.12.14, Version 0.11.16 (Unstable)

Changes since version 0.11.15:

* fsevents: remove kFSEventStreamCreateFlagNoDefer polyfill (ci-innoq)

* libuv: add more getaddrinfo errors (Steven Kabbes)

* unix: fix accept() EMFILE error handling (Ben Noordhuis)

* linux: fix up SO_REUSEPORT back-port (Ben Noordhuis)

* fsevents: fix subfolder check (Fedor Indutny)

* fsevents: fix invalid memory access (huxingyi)

* windows/timer: fix uv_hrtime discontinuity (Bert Belder)

* unix: fix various memory leaks and undef behavior (Fedor Indutny)

* unix, windows: always update loop time (Saúl Ibarra Corretgé)

* windows: translate system errors in uv_spawn (Alexis Campailla)

* windows: uv_spawn code refactor (Alexis Campailla)

* unix, windows: detect errors in uv_ip4/6_addr (Yorkie)

* stream: introduce uv_try_write(...) (Fedor Indutny)
Now working on v0.11.17
test: remove C++ style comment
stream: allow multiple buffers for uv_try_write