adding the ability to instantiate using base class & add example that parses from json encoded questions file
refactor code to use a factory method on the base class and create the correct subtypes
added load_from_dict and load_from_json factories as well as a bunch of unit tests
fix pyflakes warnings
further improvements based on feedback
Merge pull request #4 from mfwarren/master

adding the ability to instantiate using base class & add example that pa...