Last Interpreter Commit

Created by: acook

These are the last few commits before drastic changes in order to implement the VM.

It is probably possible to cherry-pick more commits from the VM branch and still get a working interpreter, such as the commit that introduces single-quote escapes in T literals, but I'll leave that for a hypothetical rainy day where we need a fully up-to-date interpreted version of blacklight, should that day ever come.