Add logging capaiblity instead of prints

[tobydragon]

This is not about logs of events (which has already been implemented), but rather having some system of replacing prints with useful logging calls that can be dynamically turned on and off. The basis for this idea is from log4j, but we want to find something similar in python.

Quick google turned up this:

http://stackoverflow.com/questions/11927278/how-to-configure-logging-in-python