Update plibc from svn

git-svn-id: https://gnunet.org/svn/gnunet@32285 140774ce-b5e7-0310-ab8b-a85725594a96
Include winternl.h, needed for testbed

git-svn-id: https://gnunet.org/svn/gnunet@32286 140774ce-b5e7-0310-ab8b-a85725594a96
Fix ats-tests makefile

git-svn-id: https://gnunet.org/svn/gnunet@32287 140774ce-b5e7-0310-ab8b-a85725594a96