ADB Over Network, integration of the adb-host mode (already present)

The feature can be used/tested without the Settings part :

  setprop service.adb.tcp.port 5555

Note: This ADB setting is not persistent (for security purpose) and
require init.rc implementation event like this : http://bit.ly/AdbTcpIP



Note : ADB_PORT setting key was added in the commit a6c11c9d

Change-Id: I5c61a53948349c785356cb5aae165110d75e3074
Signed-off-by: Tanguy Pruvot <tanguy.pruvot@gmail.com>