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.
I ran tests with it turned on, with the amount of samples (as it was), and still no faults. The main is nicely running simulation steps up to 99. So are you doing anything differently, because then we can maybe zero in on the problem?

Another thing why would we have numPupilx/y and numImagx/y, if they must be the same anyway?