Add Randlov bicycle Rl example.

I have written part of the RL bicycle problem introduced by Randlov and Alstrom as an example in PyBrain. Hopefully you all would like to include it in PyBrain!

Here's their paper: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.52.3038&rep=rep1&type=pdf

I include some plotting, so you can view the learning.

Please let me know what improvements I should make.