TcMenuDesigner: Allow users to define multiple I2C buses via UI

[vzahradnik]

Currently, the TcMenuDesigner supports configuring devices (defining addresses) on a single I2C bus. However, some devices may have multiple buses.

The code to support multiple busses is already in the library. Users can optionally supply a pointer to Wire object (WireType). This needs, however, manual initialization of the components. Support directly in the designer would be great.

Thanks!

[davetcc]

Need to get 3.1 out quickly, there is a critical bug in adafruit support that is affecting all live users. Moved to 3.2