Added more tests including network tests

I added more test methods, including testing the face registration and interest methods. I used the gevent library (http://www.gevent.org) to run threads with two faces on localhost.

I will change the lines to ut.main()

@jburkeucla 
The 0.01 is just a leftover from the original test (test_publish_async_nfd.py/test_echo_consumer.py). I can remove the argument from all sleep calls except the one on line 147, since I have to make sure the interest is registered on one face before I start expressing matching interests on another one (as far as I can tell).