Implement Lightning nuget
This change implements the lightning nuget.
It also fixes an API compatibility bug.
Merge pull request #65 from ooeygui/Dmap

Implement Lightning nuget
Fixed SPI pin configuration problems.
Set SPI pins SCK and MOSI as outputs and MISO as input.
Added SPI speeds down to 1 KHz for testing.
Fixed inaccurate SPI speed configuration problem.
Added methods to read pin directions, largely for code testing use.
Fixed some comment typos.