Refactor job_list out to its own class and improve its efficiency. Fix bugs in solver. Add negation expression.
Add simplification of unary negation.
First attmept at better tree-matching in simplify
Enable address sanitizer by default. Improve solver.
Make use of matchers in solver
Prepare for proper variable isolation.
Rewrite simplify_bin_op to use matcher pattern.
Add extra simplifiers. Working on more powerful solver.
Use priority queue for jobs.