Wrote the bytecode spec as well as a small part of the bytecode loader.
Converted the parser to use Identifier tokens inside assignments.

This is for the ease of writing a serializer to/from JSON.
Simplifed the typer by making blocks always make new scopes.
Wrote a serialization module and a "compiler" and runner.

The compiler only does the parsing and typing steps ahead of time; this
brings immesurably small (and quite probably nonexistant) speed benefits,
but I thought it would be better. Oh well.
Removed the VM code (I plan to start from scratch).

Also removed an unnecessary import.