Parsing

[wisnesky]

I tried my best to reuse code but ultimately ended up replacing much of the "plentifully typed" abstract syntax with raw, string-based syntax, probably because that's what I'm used to. I can build the rest of the parsers. However, the current parsers could use enhancement - they fail on special cases (like empty space at the front of an AQL program), comments, better error reporting, etc. I also disabled quick check for expediency, relying instead on trying examples.