Sparky: hardware update from 1.0 to 1.1

This is mostly small changes to make them easier to assemble. The
relevant user change is replacing the 4-pin receiver port that has
3.3V and VCC with a 3-pin header and a solder jumper to select
between the two, in the same way as Quanton.

This makes it easier to use a standard PPM signal and power it at
5V without modification.