Issue66

Found only a bug in the main where centLensx/y must be an array instead of a list. When this was solved the mainWFS.py worked without any errors. Also included a test function and made some adjustments to the mainWFS.py regarding the number of samples the intensity distribution has.
You turned the closed loop simulation off. That is a way to not get errors, but if I turn it on, and change the number os samples in the image plane to same amount of samples in the pupil plane (as it was)  I still get segmentation faults.

As at the end we need the loop running to get a working simulation, I won't merge this yet.