adding test.php to gitignore. It is for local testing
Removed sanitizer, replaced some of that functionality with

the Rewriter, changed node structure to be more tree-like.
It is easier to work with.
Adding types to each node for faster type checking on the values
Also, difference between array and assoc-array, so no array is called
list and assoc array is called hash.
Adding test to check Rewriter is working properly.