Add nose as a test runner.

To run the tests:

    $ python setup.py test

or, if you need to use nose plugins

    $ python setup.py nosetests --nose-options ...
Workaround bug when using nose collector for tests.

When running

    $ python setup.py test

an error is raised:

    Error in atexit._run_exitfuncs:
    Traceback (most recent call last):
      File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
        func(*targs, **kargs)
      File "/usr/lib/python2.7/multiprocessing/util.py", line 284, in _exit_function
        info('process shutting down')
    TypeError: 'NoneType' object is not callable
    Error in sys.exitfunc:
    Traceback (most recent call last):
      File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
        func(*targs, **kargs)
      File "/usr/lib/python2.7/multiprocessing/util.py", line 284, in _exit_function
        info('process shutting down')
    TypeError: 'NoneType' object is not callable

See: http://bugs.python.org/issue15881#msg170215
Updated README
Created eventlet-based UDP server

I'm not sure that this is the best approach.  However it's
functionally equivalent to the original tornado implementation I
tried and it works.