Node wrapper for Edison_OLED_Block

[bfeldman74]

I created a node addon for the OLED, SPI and GPIO classes to make them available in node applications. The API in javascript mirrors the C++ API with almost no exceptions.

The addon is published on NPM as edison-oled.

https://www.npmjs.com/package/edison-oled

I tested enough for my own personal needs and it seems to work great.

A couple of notes:

1. My C/C++ leaves a lot to be desired, so feel free to provide feedback and/or updates.
2. I think the only part of the API not implemented is EdisonSpiWrap::getCSPin becuase I couldn't get it to pass the wrapped object back properly and I don't need it.

Hope this is useful for some other folks!