Adding SPI support to LIS3MDL

I like the fact that you can pass configuration settings in the options 'option'.

Yes - it's also a bit more verbose - nothing worse than connect(SPI,D3,true,false,true,true) :)

Personally I'd stick with two connect functions for SPI and I2C. It could be merged into one as you say (and maybe should have originally) but it's nice to try and keep modules all working the same way so it's more familiar to move between them.

LIS2DH12.readXYZ - Can you give me an example?

Should just be:

lis.readXYZ(function(v) {
  console.log(v.x, v.y, v.z);
});
console.log("hello");

// prints:
//   hello
//   2,3,4