Fixes #771.

This fixes an issue where uv_spawn would not try to run a reparse point,
and continue to scan the PATH instead. Effectively, it was impossible to
spawn a symlinked binary. This commit fixes that.

Also see #748

setsockopt() doesn't touch errno on failure. Use WSAGetLastError()
instead.

This is a back-port of commit 30a8b44 from the master branch.

gcc 4.2.1 as shipped with Xcode complains incessantly about aliasing
warnings, which, while technically true, disregards the fact that the
aliased types have the same layout in memory. Squelch the warnings.

Check that a timer that is started from a check handle gets picked up
correctly, i.e. that it influences the timeout used in the next tick
of the event loop.

The `make all` target now builds both libuv.a and libuv.{so,dylib}
rather than just libuv.a.

Conflicts:
	test/test-fs.c
	test/test-list.h