move the hadoop related uid/gid configuration to a central place
Fix hbase log4j conf issue
Set Namenode listening port to default port 8020. Use fs.defaultFS for Hadoop 2.x.
Add support for configuration of topology.data.
The configuration format is: ip1 rack1,ip2 rack2, ...
When network topology changed, Namenode/Jobtracker/ResourceManager service should restart.