coros: add 2 new class: Queue and Channel to replace the existing queue
coros: add 2 new class: Queue and Channel to replace the existing queue

- Queue() is the same as previous queue()
- Channel(N) is the same as previous queue(N)
- queue(N=None) is a compatibility function that returns an appropriate instance based on N

tavisrudd/eventlet,tavisrudd/eventlet