Add checks for setlocale() and <locale.h>
diff --git a/config.h.in b/config.h.in
index 15c060b..382c46d 100644
--- a/config.h.in
+++ b/config.h.in
@@ -244,6 +244,9 @@
 /* Define if you have the setgid function.  */
 #undef HAVE_SETGID
 
+/* Define if you have the setlocale function.  */
+#undef HAVE_SETLOCALE
+
 /* Define if you have the setpgid function.  */
 #undef HAVE_SETPGID
 
@@ -310,6 +313,9 @@
 /* Define if you have the <limits.h> header file.  */
 #undef HAVE_LIMITS_H
 
+/* Define if you have the <locale.h> header file.  */
+#undef HAVE_LOCALE_H
+
 /* Define if you have the <ncurses.h> header file.  */
 #undef HAVE_NCURSES_H