Ann

Created by: sanzabizadeh

I implemented ANN to some extent. It doesn't learn yet and the example in the agents module doesn't work properly. I am merging this with the master because I want to make general changes to the code (revising docstrings and building a package instead of separate modules). Then I will continue with ANN.

Still there is no reporting or logging mechanism available. The implementation of valueset might also require some modifications.