HADOOP-7139. Allow appending to existing SequenceFiles (Contributed by kanaka kumar avvaru)

Moved to 2.6.1

(cherry picked from commit fc508b41a90a193f06a0e28ee40862bf9ee0f0c7)

Conflicts:
	hadoop-common-project/hadoop-common/CHANGES.txt

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -10,9 +10,6 @@ Release 2.7.2 - UNRELEASED
 
     HADOOP-12232. Upgrade Tomcat dependency to 6.0.44. (cnauroth)
 
-    HADOOP-7139. Allow appending to existing SequenceFiles
-    (kanaka kumar avvaru via vinayakumarb)
-
   OPTIMIZATIONS
 
   BUG FIXES
@@ -825,6 +822,9 @@ Release 2.6.1 - UNRELEASED
 
   IMPROVEMENTS
 
+    HADOOP-7139. Allow appending to existing SequenceFiles
+    (kanaka kumar avvaru via vinayakumarb)
+
   OPTIMIZATIONS
 
   BUG FIXES