Lack of void *userdata on UTPGotIncomingConnection about libutp

[ghazel]

Yes, I use the global variable approach in my own code, but I realized a parameter might be more straightforward. Would it be adequate in your case to receive the send_to_userdata which you had passed in to UTP_IsIncomingUTP, or do you need a new, second userdata*?

For my particular case, I am using the same value for the send_to_userdata and got_incoming_userdata. I am not sure whether a second userdata is worthwhile.

In terms of consistency, all of the other callbacks share the same userdata. I don't think it is too much of a stretch to have the same sharing between these callbacks.

[ghazel]

There you go: http://github.com/bittorrent/libutp/commit/43b0e2dc6f7e9bef5cccdd3ee461859af777e3da

Thanks for the feedback!