CHANGES.txt: Moving YARN-1884, YARN-3171, YARN-3740, YARN-3248, YARN-3544 to 2.6.1 given the backport.
CHANGES.txt: Moving YARN-1884, YARN-3171, YARN-3740, YARN-3248, YARN-3544 to 2.6.1 given the backport.

(cherry picked from commit f3e5bc67661ebc7e14509f2a267131ae314699dc)

Microsoft-CISL/hadoop-prototype,Microsoft-CISL/hadoop-prototype,zrccxyb62/hadoop,Microsoft-CISL/hadoop-prototype,zrccxyb62/hadoop,Microsoft-CISL/hadoop-prototype,zrccxyb62/hadoop,zrccxyb62/hadoop,Microsoft-CISL/hadoop-prototype,zrccxyb62/hadoop,zrccxyb62/hadoop,Microsoft-CISL/hadoop-prototype,zrccxyb62/hadoop,Microsoft-CISL/hadoop-prototype,Microsoft-CISL/hadoop-prototype