Begin on rewriting stats and stats output.
Move persistence things to new file
We'd like to keep `main.rs` to be argument parsing and stuff like that.
Comment out code we don't need
For some reason, the regular is faster than the exhaustive. Weird.
Don't needlessly allocate in `column_add`.
Probably still a bit of allocation going on, when the simplices vectors
are too small.
Fix plot bug, and improve stats printing
Exhaustive column reduction works, but it's implemented the dumbest way