Created a driver for the microPascal file
Added .dia and .png files for a 'High-level Conceptual Model'
* Added an updated top-level diagram.
* Created a design docs section.
* Fixes bug with IO catch
* Beginning of Scanner implementation
* The scanner base stuff should completely work. Testing and modification will likely have to be done when the FSA's are done.
* closes #17, closes #11, closes #12, closes #13, closes #14