Added test code for norbsmall and foveated norb. More on the way.

Datasets remaining to be processed on this thread:
- cos dataset
- MNISTPlus

PS: Need to check cos_dataset. Should it be transferred to create object of DenseDesignMatrix class?

I think that might be OK. Because if we provide topo_view of the data, we don't need to pass the flattened version of data_x again.