Detect presense of utmp.h and {set,get,end}utent calls.

+dnl MU_CHECK_UTMP -- Check for the presence of utmp.h, setutent, getutent
+dnl                  and endutent calls.
+AC_DEFUN([MU_CHECK_UTMP],
+[
+  AC_CHECK_HEADERS(utmp.h)
+  # The three functions setutent,getutent and endutent depend on each other,
+  # so it seems reasonable to provide replacements for all three if getutent
+  # is not present.
+  AC_CHECK_FUNC(getutent,
+                 AC_DEFINE(HAVE_GETUTENT_CALLS,,
+         [Define if your system has the three ???utent functions]),
+                 [if test "$ac_cv_header_utmp_h" = "yes"; then
+                   LIBOBJS="$LIBOBJS utmp.o"
+		 fi])])