Allow each Arduino to have both Input and Output devices

[antoinepetty]

Currently the code is fixed for Ard_T and Ard_M to have Output objects, and Ard_I to have Input objects. Should allow for any Arduino to have both input and output devices attached.

One example for this use is to allow for the Sonar to be controlled via JSON

This would negate the need for certain conditional statements and the hardcoded main loop control for Ard_I

[antoinepetty]

Might need Input and Output to inherit from a core Device class with a control method

[antoinepetty]

Changed size to large because this could involve some smart decisions and therefore more code changes

[antoinepetty]

See generic-device-base-class branch

[antoinepetty]

This is not a high priority feature. The code will function fine without it.