integration of POT, LCD and relay control.

This utilizes a POT to set the temperature, and LCD to display state
and a relay to control the output.  It uses a PID algorithm to control
heating/cooling.  This is not yet tested on fully integrated hardware.
code cleanup and SD card support and Ethenet support

The SD card and Ethernet support are too large for my LeLeonardo, so
they have not been tested.  I will likely test these when I get back to
using my Mega or Due.
cleanup and relay pin change due to box constraints