HDFS-4516. Client crash after block allocation and NN switch before lease recovery for the same file can cause readers to fail forever. Contributed by Vinay.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543829 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5014. Process register commands with out holding BPOfferService lock. Contributed by Vinay.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543861 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5525. Inline dust templates for new Web UI. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543895 13f79535-47bb-0310-9956-ffa450edef68
Merging r1543710 through r1543901 from trunk to branch HDFS-2832

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2832@1543902 13f79535-47bb-0310-9956-ffa450edef68