C4.5 notebook added, C4.5 missing stopping criteria added

- C4.5 notebook added
- stopping criteria added for all same attributes

[Notebook output](http://nbviewer.ipython.org/gist/mazumdarparijat/3e3a812cc3b91b605d66)
I guess you already tried, but didn't this work fine using Shogun's CSVFile class?