Design a CAN shield for MBED

[peplin]

Drop an MBED in a DIP socket and add:

• CAN transceivers
• CAN headers
• Port for RN-42 (check that the UART pins are available on the MBED)
• Jumper or toggle for selecting CAN pins (CAN1, CAN2-1, CAN2-2)
  • Alternatively, could we have a 3rd transceiver wired up to a 3rd set of CAN pins?

[peplin]

This will be identical to the shield designed in #4, but the layout will be different - it'll have a DIP socket for the MBED instead of having male pins to sit on top of the chipKIT as a shield.