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
You can write `(1./C)*Id)` as `(1 / C) * Id)`, it seems to fit in 80 chars. Also, I'm rather used to `I` rather than `Id` but I guess `Id` is clear.