Things to do:
done: Allow expressions for state type & value.
done: Allow expressions for drive type & value.
done: Eliminate filler in drive record.
Introduce InstructionRecords, which use BOOLs (along with drive bits) to instruct switch values.
done: Drive records get {Drive, Ignore, Test} instead of BOOLs.
Classify TestProcs as Rosemary-tests-em or Proc-tests-em.
done: Allow initialData and initialValue (with format) on node instantiations.
done: Change to named testprocs.
done: Add tag field to drive records.
done: Change allocation of drive records.
done: Add initialization of drive records.
done: Change drive records to use arrays instead of names fields.