Change RocksDB version to 4.1

Summary: Change RocksDB version to 4.1

Test Plan: no code change.

Reviewers: sdong, anthony, IslamAbdelRahman, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D48387

HISTORY.md

@@ -1,6 +1,6 @@
 # Rocksdb Change Log
 
-## Unreleased
+## 4.1.0 (10/8/2015)
 ### New Features
 * Added single delete operation as a more efficient way to delete keys that have not been overwritten.
 * Added experimental AddFile() to DB interface that allow users to add files created by SstFileWriter into an empty Database, see include/rocksdb/sst_file_writer.h and DB::AddFile() for more info.

include/rocksdb/version.h

@@ -5,7 +5,7 @@
 #pragma once
 
 #define ROCKSDB_MAJOR 4
-#define ROCKSDB_MINOR 0
+#define ROCKSDB_MINOR 1
 #define ROCKSDB_PATCH 0
 
 // Do not use these. We made the mistake of declaring macros starting with