HADOOP-8711. Provide an option for IPC server users to avoid printing stack information for certain exceptions. Contributed by Brandon Li.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1478426 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-8711. Add a missing file in previous commit r1478426

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1478429 13f79535-47bb-0310-9956-ffa450edef68
HDFS-3817. Avoid printing stack information for SafeModeException. Contributed by Brandon Li.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1478433 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4774. Backport HDFS-4525: Provide an API for knowing whether a file is closed.  Contributed by Ted Yu


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1478517 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9543. TestFsShellReturnCode may fail if the hardcoded user "admin" is not a valid user in the loacl OS.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1478524 13f79535-47bb-0310-9956-ffa450edef68