Settings Implementation

Allows full configuration of Network, PIN and Door without editing or
even creating CFG files.
-Network will generate random MAC and use DHCP by default setting and
store into EEPROM if no NETWORK.CFG file is present
-Default pins.cfg file generated if not present
-RSV pins can not be assigned via Settings
-Free configuration of doors.cfg via web page, device updates only with
properly formed JSON
Assigning a random MAC allows never having to assign a MAC (possibly gold plating but very useful if DHCP is all that is used for multiple Arduinos).

I ordered two board+shield combos that did not include stickers for their MAC address. I was also interchanging SD cards so I wanted the MAC fixed to the hardware and not the card (or dependant on hardcoding).

Since the random MAC was a feature I implemented before adding the web interface to assign it, I will remove it and go with a fixed MAC that can be changed if needed. To assign the full MAC, the config file will be necessary.