pika/pika — pull request #389 by anton-ryzhov (2013-08-18 18:09:12+00:00)
Title: Lazy import Tornado, Twisted and Libev

I've changed 3rd-party libraries import mechanism. Now pika loads all libraries and holds it in the memory even if it doesn't use it.

Now it loads corresponding library on first usage. It doesn't catch ImportError`s, because developer definitely has to have corresponding library before using adapter its.