Adding 2.0.5-alpha release to CHANGES.txt files of branch-2

Also updating current version to 2.1.0-beta in the CHANGES.txt files

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488585 13f79535-47bb-0310-9956-ffa450edef68
Setting artifact versions to 2.1.0-SNAPSHOT to refrecl recent release of 2,0.5-alpha

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488586 13f79535-47bb-0310-9956-ffa450edef68
YARN-717. Put object creation factories for Token in the class itself and remove useless derivations for specific tokens. Contributed by Jian He.
MAPREDUCE-5289. Updated MR App to use Token directly after YARN-717. Contributed by Jian He.
svn merge --ignore-ancestry -c 1488616 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488617 13f79535-47bb-0310-9956-ffa450edef68
YARN-733. Fixed TestNMClient from failing occasionally. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1488618 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488619 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5229. Put back FileOutputCommitter.TEMP_DIR_NAME in mapreduce for binary compatibility with 1.x APIs. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1488621 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488623 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5274. Bring back SecureShuffleUtils.toHex in mapreduce for binary compatibility with 1.x APIs. Contributed by Mayank Bansal.
svn merge --ignore-ancestry -c 1488625 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488626 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-MAPREDUCE-4884-branch-2-gd