Corrected the examples and rewrote them using IPython Notebook files.

1. Examples (.py) in the (old) `examples/` directory have been corrected and rewritten using IPython Notebook file.
2. Corresponding `.ipynb` files are stored in `examples/notebook` and the (old) `.py` files in the `examples/` have been replaced with the cleaner ones as exported from their respective IPython Notebooks and have been moved to `examples/source`.
3. `.rst` files of these IPython notebooks are stored in the directory `docs/source/modules/usage/`.

This is a sample of the rendered IPython file : [BinaryCounter.ipynb](http://nbviewer.ipython.org/gist/rvraghav93/10740725)