Patch #976880: add mmap .rfind() method, and 'end' paramter to .find().
Contributed by John Lenton.
diff --git a/Misc/ACKS b/Misc/ACKS
index 499b1d0..35cecee 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -395,6 +395,7 @@
 Joerg Lehmann
 Luke Kenneth Casson Leighton
 Marc-Andre Lemburg
+John Lenton
 Mark Levinson
 William Lewis
 Robert van Liere