Revert "darwin: merge uv_cond_timedwait implementation"

Using mach_absolute_time() for the pthread_cond_timedwait() timeout
breaks a number of tests on OS X 10.8.2.

This reverts commit 8311390f13177f3086ecdac875115d2d4cc2688b.
unix: remove scandir prototype workaround in fs.c

It's not necessary for newer OS X releases and I don't care enough
about OpenBSD to squelch the warning.
darwin: merge uv_cond_timedwait implementation

This is a revised version of commit 8311390.
win: Avoid using subversion to download gyp
darwin: make uv_cond_timedwait() clock skew safe

Use pthread_cond_timedwait_relative_np() so we're not prone to spurious
bugs caused by clock skew.
stream: use kevent() information before accept()

Limit number of syscalls by using backlog length information provided by
kevent().
unix,windows: fix timer order in case of same timeout

Compare start_id of timer handles when they have the same timeout.
start_id is allocated with loop->timer_counter in uv_timer_start.
unix, windows: make uv_fs_t.statbuf public

Make the statbuf field public. This means you no longer have to use
req->ptr - though that still works and will continue to work for the
foreseeable future.

Fixes #704.