DeviceManager now tries to retrieve DeviceConfig using serial chip ID first, then MAC (for 'TR doesn't recognize iSense nodes when MAC broken' #352).
Resetting MAC address if broken for #352 (TR doesn't recognize iSense nodes when MAC broken)

MAC address reset is triggered if the configured MAC (from DeviceConfig) does not match the actual MAC address. The check for this is done at two stages:

1. When DeviceManager uses SingleDeviceAdapter to connect to a node the adapter.
2. When an image is being flashed to a node and this process either succeeds, fails or gets cancelled.
Resetting broken MAC address on Gateway startup and after flash operations (for #352), only tested on iSense on Mac OS X so far.

Whenever a SingleDeviceAdapter connects to a device it will check if devices' MAC address in the DeviceConfig is equal to the actual MAC address reported by the device. If not it will try to reset the device MAC address to the address configured in the DeviceConfig. The same happens when a user flashes a device. After the process the gateway will check if the device MAC is still intact and trigger the reset functionality if needed.
Added dev-config for gateway process to configure log4j
Not trying to do broken MAC reset for devices not supporting reading/writing MAC addresses like Telos B  (for #352)