Increase build version and HISTORY.md for releasing 5.2

Summary:
Also clean up HISTORY.md a little bit.
Closes https://github.com/facebook/rocksdb/pull/1854

Differential Revision: D4539556

Pulled By: siying

fbshipit-source-id: 567391e

HISTORY.md

@@ -1,15 +1,26 @@
 # Rocksdb Change Log
 ## Unreleased
+
+## 5.2.0 (02/08/2017)
 ### Public API Change
-* Support dynamically change `delete_obsolete_files_period_micros` option via SetDBOptions().
-* Added EventListener::OnExternalFileIngested which will be called when IngestExternalFile() add a file successfully.
-* BackupEngine::Open and BackupEngineReadOnly::Open now always return error statuses matching those of the backup Env.
-* Added new overloaded function GetApproximateSizes that allows to specify if memtable stats should be computed only without computing SST files' stats approximations.
 * NewLRUCache() will determine number of shard bits automatically based on capacity, if the user doesn't pass one. This also impacts the default block cache when the user doesn't explict provide one.
 * Change the default of delayed slowdown value to 16MB/s and further increase the L0 stop condition to 36 files.
-* Added new function GetApproximateMemTableStats that approximates both number of records and size of memtables.
 * (Experimental) Two-level indexing that partition the index and creates a 2nd level index on the partitions. The feature can be enabled by setting kTwoLevelIndexSearch as IndexType and configuring index_per_partition.
 
+### New Features
+* Added new overloaded function GetApproximateSizes that allows to specify if memtable stats should be computed only without computing SST files' stats approximations.
+* Added new function GetApproximateMemTableStats that approximates both number of records and size of memtables.
+
+### Bug Fixes
+* RangeSync() should work if ROCKSDB_FALLOCATE_PRESENT is not set
+* Fix wrong results in a data race case in Get()
+* Some fixes related to 2PC.
+
+## 5.1.0 (01/13/2017)
+* Support dynamically change `delete_obsolete_files_period_micros` option via SetDBOptions().
+* Added EventListener::OnExternalFileIngested which will be called when IngestExternalFile() add a file successfully.
+* BackupEngine::Open and BackupEngineReadOnly::Open now always return error statuses matching those of the backup Env.
+
 ### Bug Fixes
 * Fix the bug that if 2PC is enabled, checkpoints may loss some recent transactions.
 * When file copying is needed when creating checkpoints or bulk loading files, fsync the file after the file copying.

include/rocksdb/version.h

@@ -5,7 +5,7 @@
 #pragma once
 
 #define ROCKSDB_MAJOR 5
-#define ROCKSDB_MINOR 0
+#define ROCKSDB_MINOR 2
 #define ROCKSDB_PATCH 0
 
 // Do not use these. We made the mistake of declaring macros starting with