HADOOP-10312 Shell.ExitCodeException to have more useful toString

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1607591 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9361: Strictly define FileSystem APIs

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1607596 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9361: Strictly define FileSystem APIs - HDFS portion

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1607597 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9361: Strictly define FileSystem APIs - OpenStack portion

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1607599 13f79535-47bb-0310-9956-ffa450edef68