Improve friendliness of --cmdhelp

If no match is found, print the closest. Quite handy when
you can't quite remember the exact option name.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/parse.h b/parse.h
index 214e56b..1a71864 100644
--- a/parse.h
+++ b/parse.h
@@ -67,4 +67,11 @@
 
 #define td_var(start, offset)	((void *) start + (offset))
 
+#ifndef min
+#define min(a, b)	((a) < (b) ? (a) : (b))
+#endif
+#ifndef max
+#define max(a, b)	((a) > (b) ? (a) : (b))
+#endif
+
 #endif