o Minor fixes (threads, comments):
    - Remove undefined directive-in-macro in test_util_writepid
      clang 3.7 complains that using a preprocessor directive inside
      a macro invocation in test_util_writepid in test_util.c is undefined.
      Patch by "teor". Fixes part of bug 16115; bugfix on 0.2.7.1-alpha.