[Code Review Request] EAGLE-14 Re-assemble high level hdfs commands for better policy

[Zhang, Edward (GDI Hadoop)]

I would like to request code review for 
https://issues.apache.org/jira/browse/EAGLE-14
The pull request is in 
https://github.com/apache/incubator-eagle/pull/19/files?diff=split

After review, please comment and then merge.

Thanks
Edward