Asyncio cleanups

Optimizations, featuring prefetch

Bye bye Promise.

Also fixed a comment.

Useful for playing with ssl configurations and generally for being
able to inspect server state in development and testing.

This only makes sense when running the server in a thread, of course.

Useful for playing with ssl configurations.

Also added a comment with a reminder for how to create self-signed certs.

Useful for playing with ssl configurations.

IOW, if there's an outstanding call is made for a given oid and tid,
and another call is made, the second call will use the result of the
outstanding call, rather than making another call to the server.

And move this file to the top of the project, as there was a similar
version ther.

Python 2 support

After reading run_until_complete doc :)

Conflicts:
	setup.py
	src/ZEO/asyncio/base.py

Uvloop

Conflicts:
	setup.py

Client side conflict resolution

TCP_NODELAY

Conflicts:
	setup.py
	src/ZEO/tests/protocols.test

See: https://github.com/zopefoundation/ZODB/issues/84

I'm losing my love of stubs. :(