progsys Digits problem

[mfjoneill]

In some cases the fitness can exceed sys.maxsize and cause a run to abort.
I will create a pull request to fix this in general for all progsys problems by adding a new condition in evaluate() progsys.py:

 	if 'quality' in result:
        if result['quality'] > sys.maxsize:
            result['quality'] = sys.maxsize