DO NOT MERGE: Implement device discovery sequence.

When device discover is launched it goes through the following step

1. clear all existing devices
2. send <Polling Message> of all logical addresses
  excecpt one of local device
3. Once got all allocated logical addresses, gather physical address of
  them
4. Once got physical address of them, gather display name of them
5. Once got display names, gather vendor id of them
5. Once got vendor id of them, register all gathered info to
  internal device info list.

Change-Id: Ic9aca3b15d88ac7650f10b6d0bfa9c97923975e8