Enable akka cluster mode
support master HA
optimize the imports
HA
add master log
master ha
master HA
refactor the contants
Refine the cluster message
master HA
fix ha bug
merge with intel-hadoop/gearpump
fix merge issue
fix compile issues
fix command line options for shell commands
fix client app shutdown bug
add more logs
fix HA bug
Update README.md
fix readme documents