Added the iris dataset image to supervised_learning.rst
Added html for iris dataset image.
Updated plot_iris_classifiers.py to use KNearestNeighbors
plot_iris_dataset_3class.py is for the image of the iris dataset
- Didn't want to overwrite plot_iris_dataset.py just yet.
Few links added into supervised_learning.rst
image in settings.rst now square so doesnt shrink adjacent code box
updated ipython code regarding nearest neighbours(after API change in 0.10)