Simplify value of INSTALL (always 'cp').
Pass value of OPT from configure environment to Makefile.
Add check for limits.h.
Use <directory>/libreadline.a instead of -lreadline.
diff --git a/config.h.in b/config.h.in
index ff6490e..a3fc506 100644
--- a/config.h.in
+++ b/config.h.in
@@ -225,6 +225,9 @@
/* Define if you have the <fcntl.h> header file. */
#undef HAVE_FCNTL_H
+/* Define if you have the <limits.h> header file. */
+#undef HAVE_LIMITS_H
+
/* Define if you have the <signal.h> header file. */
#undef HAVE_SIGNAL_H