light-netsender: Add a feature to be able to have multiple LED lights per device controllable through VidGrind.

[Ella Di Stasio]

Issue #62 developed a simple control of one LED light using light-netsender, this feature extends the use to separate control of multiple LED lights (i.e. control multiple GPIO pins). This includes two aspects, the first is to have unique controlled of multiple and individual GPIO pins, and the second aspect is to have one control over multiple GPIO pins.