Added additional information to gampad devices

[ghost]

I have a situation requiring all data in struct input_id to be returned to node.js. I made these changes on a local branch and figured I would share:

struct input_id {
	__u16 bustype;
	__u16 vendor;
	__u16 product;
	__u16 version;
};

Thanks for the great library. Let me know if you need anything further.