Added sig_atomic_t.

acconfig.h

 /*
- * $Id: acconfig.h,v 1.6 1999/05/24 09:33:53 ceder Exp $
+ * $Id: acconfig.h,v 1.7 1999/06/25 21:21:11 ceder Exp $
  * Copyright (C) 1998-1999  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -49,6 +49,10 @@
 /* Define if your OS has struct sigaction */
 #undef HAVE_STRUCT_SIGACTION
 
+/* Define this to a type that can be changed atomically from a signal
+   handler if your OS lacks sig_atomic_t.  */
+#undef sig_atomic_t
+
 /* Define if on HPUX */
 #ifndef _HPUX_SOURCE
 #undef _HPUX_SOURCE