[WarehouseManagementSystem] Rename WHCommandClient.java to WHRobotInf.java

renamed:
WarehouseManagementSystem/src/com/lge/spartan/warehouse/WHCommandClient.java -> WarehouseManagementSystem/src/com/lge/spartan/warehouse/WHRobotInf.java
[WarehouseManagementSystem] WHRobotMonitor: add monitor of robot status

WHRobotMonitor monitors status of robot HW. Robot HW exports
the status about station arrival, ping-echo, and watchdog.
Once WHRobotMonitor sends the message to robot, robot HW responds
the result about that message, which returns true or false.
WHRobotMonitor also serves function of showing the status of robot
to Order Processor. APIs are implemented on both sync and async.
[WarehouseManagementSystem] WHRobotInf: change for integration with WHRobotMonitor