Update HISTORY.md to include TimeOut write API and compaction update.

Summary: Update HISTORY.md to include TimeOut write API and compaction update.

Test Plan: n/a

Reviewers: ljin, sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19449

HISTORY.md

@@ -4,7 +4,8 @@
 
 ### New Features
 * HashLinklist reduces performance outlier caused by skewed bucket by switching data in the bucket from linked list to skip list. Add parameter threshold_use_skiplist in NewHashLinkListRepFactory().
-
+* RocksDB is now able to reclaim storage space more effectively during the compaction process.  This is done by compensating the size of each deletion entry by the 2X average value size, which makes compaction to be triggerred by deletion entries more easily.
+* Add TimeOut API to write.  Now WriteOptions have a variable called timeout_hint_us.  With timeout_hint_us set to non-zero, any write associated with this timeout_hint_us may be aborted when it runs longer than the specified timeout_hint_us, and it is guaranteed that any write completes earlier than the specified time-out will not be aborted due to the time-out condition.
 
 ## 3.2.0 (06/20/2014)