Break inclusion cycles. To simplify the change, move a few

declarations to other, no less sensible places.

include/optlist.h

@@ -35,6 +35,8 @@
 #ifndef _OPTLIST_H_
 #define _OPTLIST_H_
 
+#include "nsc.h"
+
 struct option_list {
     char *opt_key;
     int *opt_valuep;