Fix compile issue caused by change in mainline Arduino IDE.

Commit came from here:
https://github.com/sirleech/Webduino/commit/3125b21fa9d2b246d7f61b5eafa3db61eaccb015

Broken commit in newer versions of arduino IDE:
https://github.com/arduino/Arduino/commit/ca37de4ba4ecbdb941f14ac1fe7dd40f3008af75
Update Network sketches to have a new default mac address per rules on
their behavior.  For more information, see Jon Chuchla's post here:
http://diychristmas.org/vb1/showthread.php?2760-Can-t-ping-komby-sandwich&p=31396&viewfull=1#post31396

Also add the ability to use DHCP for the OTA Configuration sketch.