Include util/thread.h before util/util.h in util/thread*.cc.

Having it the other way around was reported to cause build failures with
MSVC. The definition of WIN32_LEAN_AND_MEAN in util/mutex.h might be the
culprit, but it's clear that this solution works for @DThiebaud.

Fixes #53.

Change-Id: I66adc10e7260ec52be06dd1a68e9221ff1c5a3ca
Reviewed-on: https://code-review.googlesource.com/3530
Reviewed-by: Paul Wankadia <junyer@google.com>
2 files changed