WFS update, and added function for rectangular setups in the main

Increased the readability of mainWFS.py.
Normalized the intensity distribution and the lensletCentx/y.
Added support length for FFT in the parameters for the sensors.
Added function in main to handle rectangular lenslet configurations.
 
@JaccovdS: Sorry, you are not using the data.
@herminarto: You receive the data from the WFS. What is necessary? What do you expect?