MAPREDUCE-5488. Changed MR client to keep trying to reach the application when it sees that on attempt's AM is down. Contributed by Jian He.
svn merge --ignore-ancestry -c 1524856 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1524857 13f79535-47bb-0310-9956-ffa450edef68
YARN-1203. Changed YARN web-app proxy to handle http and https URLs from AM registration and finish correctly. Contributed by Omkar Vinit Joshi.
MAPREDUCE-5515. Fixed MR AM's webapp to depend on a new config mapreduce.ssl.enabled to enable https and disabling it by default as MR AM needs
to set up its own certificates etc and not depend on clusters'. Contributed by Omkar Vinit Joshi.
svn merge --ignore-ancestry -c 1524864 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1524867 13f79535-47bb-0310-9956-ffa450edef68