Add the intro.ipynb notebook

Fix verify_query in tests/test_text.py to work with Windows file-paths

Implementation of Perceptron Learner

IPython Notebook for games.py

Implementation of cross_validation_wrapper.

Improvements, corrections and tests for games.py

Get branch even with latest changes in master

# Conflicts:
#	tests/test_utils.py
#	utils.py

Revised Implementation of backpropagation, util func

Improved test for and_or_search