Robotjs: Implement callbacks

[Multiply]

I want to do something like

robot.moveMouseSmoothly(x, y, function(coordinates, oldCoordinates) {
  console.log('Done moving');
});

Would this be possible to do for all methods, so we can chain them properly, and so the methods are not blocking.

[octalmage]

This is probably way better than #14, it's the Node.js way to do things.

Thanks for the suggestion, I'll keep it in mind.

[kilianc]

Better if returns a promise, a callback that doesn't have err as first parameter is not standard and not yieldable :)

Looks like we have no err to report, and having always nil seems unnecessary

[octalmage]

I'm still not sure how I should handle this, but I think it would be best to use callbacks with a delay in the C code. This way the commands are chainable, the delay is non-blocking, and we won't run into any OS limitations.

[skibz]

callbacks :+1:

[marcio199226]

Will be this feature implemented in any future releases ?

[ricardopolo]

Promises, async/await 👍