Changed the noted typos in NumPy and revised Exercise 8
Bunched the first 3 exercises of Pandas and added Further Resources section
Added Further Resources to Networks and Scipy notebooks
Anonymised recordings made by me for the Scipy notebook
Added licensing info for audio files used in the Scipy notebook
Deleted some clutter (an old attlist file which is superceded, and the extra-exercises which were a bit of a holding area and aren't really part of the course)