Rewrite Parsing Code

[troiwilliams]

The parsing code (in the Parsing directory) was written in a hurry so that a user can write a Kodu program without having to recompile each time he or she altered it. Most of the code was not cleanly designed, which makes it hard to understand what the code is doing at times. There is also much copy-and-pasted code that makes the code unnecessarily longer and inefficient. Thus, the parsing code must be rewritten.