[MRG] GSoC 2014: Standard Extreme Learning Machines

Finished implementing the standard extreme learning machines (ELMs). I am getting the following results with 550 hidden neurons against the digits datasets,

Training accuracy using the logistic activation function: 0.999444
Training accuracy using the tanh activation function: 1.000000

Fortunately, this algorithm is much easier to implement and debug than multi-layer perceptron :).
I will push a test file soon.

@ogrisel , @larsmans
This plot has weird color background:

![plot_weighted_elm_001](https://cloud.githubusercontent.com/assets/89061/3964112/de93b6fe-2784-11e4-963e-c4a39f9e2e9b.png)

The decision boundary does not always seem to lie in the white area. Can you please try to fix it?