[Feature request] Add support for multiple Controllers

[Managor]

Would be nice if the program detected several controllers and used all the available tracks.

[Roboron3042]

It would be fantastic, but not so many have access to more than one controller. I myself don't, so I can not implement this myself!

[Managor]

I have literally no experience with this sort of stuff, but I'll take a look if I have the time.

[Roboron3042]

Currently device is accessed using libusb_open_device_with_vid_pid, but that only works for one device. For more, one would need to call libusb_get_device_list and find the controllers (I don't know the details).

Then you would need to refactor various parts of the code so everywhere an action is done on the controller, it is done on each one of the controllers in the previous list (open, claim, close, etc...).

On playSong you need to adjust the for loop, so it will keep going after channel 1 if there is more than one controller, and assign a new controller each 2 channels.

I don't know if sync would be a issue. Hopefully not!