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
Yes, sorry I should have updated this statement since we no longer have the parameter ``algorithm``.
This will be the new tip,

**Setting batch_size**: if the dataset cannot fit into memory, it is 
    desirable to set ``batch_size`` to a small value. However, smaller ``batch_size``
    might increase training time.