fix: state-machine size explosion on wildcards

[timbray]

Certain combinations of shellstyle patterns cause an explosion in the size of the state machine along the lines of O(2**N). The effect is that AddPattern() can take seconds to execute and burn memory. We know this is not inevitable because AWS Event Ruler can build this kind of machine quickly and economically.

Initial thoughts:

1. Characterize the problem properly
2. Make nice String() on smallTable and related types
3. Replace list_maker with something much better thought through - it's a hack
4. Fix the problem