Principled way of scheduling rewrites

[kris-brown]

We need a less ad-hoc way of organizing collections of rewrite rules (e.g. executing rules in sequence and while a condition holds, also the difference between executing for a single vs all matches in some order).

This issue can serve to collect ideas / papers that could help

https://www.researchgate.net/publication/324038143_The_Art_of_Iterating_Update-Strategies_in_Agent-Based_Simulation

[kris-brown]

addressed by #15