Significant API changes, experimental deck support. * Experimental `Deck` class. API still very unstable. * `Pool`s, `Deck`s, and internal Alignment now have a common base class `OutcomeCountGen`. * `EvalPool` renamed to `OutcomeCountEval`. * `Die` and `Deck` are now proper `Mapping`s with `keys`, `values`, and `items`. * The above view types can also be accessed like sequences. * A `Die` is now always considered not `equal()` to non-`Die`. * `die[]` now works like a dict. Use `marginals[]` to marginalize dimensions. * `Die`, `Pool`, and `Deck` now take a single sequence or mapping argument rather than a variable number of arguments. * `Die`, `Pool`, and `Deck` now all have the same name for the second argument: `times`. * `count_dice` renamed to `post_roll_counts`. No longer accepts `None`, use `[:]` instead. * Linear algorithm for comparators on `Die`. * Improvements to internal `Count` class. * Add `clear_pool_cache` function. * Forward `*extra_args` for `reroll, reroll_until, explode`.