Port of the Tulip project (asyncio module, PEP 3156) on Python 2

Trollius provides infrastructure for writing single-threaded concurrent code using coroutines, multiplexing I/O access over sockets and other resources, running network clients and servers, and other related primitives. Here is a more detailed list of the package contents:

* a pluggable event loop with various system-specific implementations;
* transport and protocol abstractions (similar to those in Twisted);
* concrete support for TCP, UDP, SSL, subprocess pipes, delayed calls, and others (some may be system-dependent);
* a Future class that mimics the one in the concurrent.futures module, but adapted for use with the event loop;
* coroutines and tasks based on generators (yield), to help write concurrent code in a sequential fashion;
* cancellation support for Futures and coroutines;
* synchronization primitives for use between coroutines in a single thread, mimicking those in the threading module;
* an interface for passing work off to a threadpool, for times when you absolutely, positively have to use a library that makes blocking I/O calls.

Trollius works on Python 2.6-3.5. It has been tested on Windows, Linux, Mac OS X, FreeBSD and OpenIndiana.