* configure.in (LIBMUDFLAPTH): Fix thinko.
* configure.in: Check for more headers.
* mf-hooks2.c: Conditionalize on HAVE_SYS_SOCKET_H etc.
* mf-runtime.c: In two places conditionalize on SIUSR1 rather than
HAVE_SIGNAL as mingw has signal.h but not SIUSR1.
From-SVN: r82627