Adding HDFS connector

HDFS(Hadoop FIle System) is widely use in big data system.
I think it might be helpful if we provide connecting method to HDFS.
It works like File Connector but using inotify(see HDFS-6634) instead of Watch Service(in Java nio)
I wondering it will be helpful in Quarks or not. If any commiter can review the usefulness of this function, please tell me. Then I will start to work.