CANServer Hardware v2

Version two of the CANServer board adds support for an optional second CAN bus daughter card, a push/pull microSD slot, 3.3V IO, and various fixes. Make sure the ESP32 board is in the rightmost 19 pin sockets (the 20-pin sockets are common stock). The main CAN bus connector is on the lower left, and is common with the center yellow chassis connector (including 12v power) if present. The secondary CAN bus connector is on the top left, and does not power the board.