We should be able to delay the clipboard packets and only send the latest token.
ie: when the user is changing the primary selection by moving the mouse we can easily get 30+ requests per second.
We should queue them up and replace all the token packets with the latest one.
And if we get a token back from the other end, we should cancel sending the token entirely! (after comparing timestamps)
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2404