Fix the monkey-patching of the threading module on Python 3.4. Instead
of removing the thread state lock, patch the _bootstrap_inner() method
to release it.

The "py{27,34,py}-dns" syntax in envlist is only supported on tox 1.8 or
newer.

For the Python implementation of threading.RLock because the new C
implementation of threading.RLock of Python 3.3 is not compatible with
eventlet monkey patching.

Fix the issue #185.

* I ran into issues where, when passing DNS messages through a proxy with
eventlet 0.17.1 sockets would be prematurely closed. This was not the case in 0.16.1.
This fixes the issue

Provide a compatibility layer in eventlet.wsgi that allows you
to hand a python logger as the log parameter instead of a
filehandle.

If an object that looks like a python logger is passed, we use
it as expected. If not, we assume this is a fileobject that
implements the write() call, and wrap it in a compatiblity layer
that lets us user log() and debug() calls on it, including
optional *args.

https://github.com/eventlet/eventlet/pull/75

https://github.com/eventlet/eventlet/issues/219