This commit is the result of many days of picking vm apart and putting
it back together again. The result is an implementation which separates
compile and runtime into separate steps, and which functions (more)
correctly in the face of recursion.
Pretty much all aspects of vm have been modified or deleted, so it's not
even really worth it to describe specific changes. Just pretend this is
the original implementaiton and the old one was never done.
The vm does what it needs to do (evaluate the result of passing an input
to an operatio, where the input and the operation themselves may have
sub-inputs/operations to evaluate), with many caveats/misgivings.
