Asyncio interface

[kszucs]

If I recall correctly there were plans about dropping tornado and use python's native asyncio coroutines. @Arttii are You still interested?

[Arttii]

I dunno, I didn't feel like there is much demand. I do feel like there would be more interest if it was implemented in asyncio, but it complicated time wise. The conversion should be fairly simple though. Do you need the asyncio func or just interested? We could always jesus it and implement it in curio and be super hipster.