Clean up match forms, switch to define/match
Switch to a single astack per instruction
Use configurations
Add time stamped configurations

This increases run-time significantly because integer comparison is
significantly faster than comparing two environments
Implement separate register environments for each insn
Refinement proceeds when the value is strictly greater than the new one
Glaring typo, causing significant problems

With the previous definition it always returned true.
Correct the new-info? requirement for join-env

If the previous register environment NEITHER subsumes NOR equals the new
register environment, then there is new information.