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)
the trained tree or a trained tree. If you want, proof read and pay attention to this type of mistake, from now on I will skip it.