Icepool

* Deprecate `depth=None` in favor of `depth='inf'`.
* Add experimental `format_inverse()` option that formats probabilities as "1 in N".

* Add `pointwise_max`, `pointwise_min` arguments to take pointwise maximum or minimum of CDFs.
* Add `Die.time_to_sum()` method.
* Fix identification of absorbing states in the presence of `extra_args` in `map_and_time()`.
* Add `time_limit` parameter to `map()`.
* `repeat` parameter now uses `'inf'` to request the absorbing distribution rather than `None`.

* Breaking change: outcomes with zero quantities are removed when constructing `Die` and `Deck`.
* Functions and methods relating to zero-quantities are removed: `align()`, `align_range()`, `Population.has_zero_quantities()`, `Die.trim()`, `Die.set_range()`, `Die.set_outcomes()`.
* You can use `consecutive()` or `sorted_union()` to get an appropriate superset of sets of outcomes.
* Breaking change: `MultisetEvaluator.alignment()` is renamed to `MultisetEvaluator.extra_outcomes()`.
* `MultisetEvaluator.range_alignment()` is renamed to `MultisetEvaluator.consecutive()`.
* The `Alignment` class is no longer public.
* Breaking change: `Deck.multiply_counts()` and `Population.scale_quantities()` are replaced/renamed to `Population.multiply_quantities()` etc.
* Add `Deck.sequence()` and `Die.sequence()` method.
* Add `Population.pad_to_denominator()` method.
* Move `zero()` and `zero_outcome()` from `Die` to `Population`.
* `` operator now sums left-to-right.
* Remove old `compair` evaluation.
* `min_outcome()` and `max_outcome()` free functions can now be called using a single iterable argument.
* Forward algorithm now has a persistent cache.
* Add skip optimization for single deals with keep tuples.
* Pools now only skip dice, not outcomes. This is a bit slower in some cases but provides more consistent iteration order.
* Add shared evaluator instances for some built-in evaluator for caching.
* Simplify determination of outcome order for multiset evaluations.
* Simplify implementation of generator unbinding.
* Fix `extra_args` expansion for `map_and_time`.

* Providing only a `drop` argument to `lowest()` or `highest()` will now keep all other elements rather than just the first non-dropped element.
* `depth` argument to `Die.reroll()` is now mandatory.
* `tuple` outcomes are now auto-`tupleize`d again during `Die` construction.
* Add `Die.stochastic_round()` method.
* Add `Die.reroll_to_pool()` method.
* Add `Die.keep()` method. This works as `MultisetGenerator.keep()` with an implicit sum.
* Add `percent` option to `Population.probability`.
* Add new `again_count` mode for handling `Again`, which limits the total number of dice.
* Improved ability to `keep` from both ends for certain types of multiset expressions.
* Rename `func` parameters to `function`.
* `MultisetExpression.order()` is now public.
* Improved sorting for `Symbols`; now compares counts in alphabetical order.
* Experimental `sort_match`, `maximum_match_highest`, `maximum_match_lowest` expressions. `sort_match` replaces the `compair` evaluations.
* Experimental `all_straights_reduce_counts` and `argsort` multiset evaluations.
* Breaking change: `nearest`, `quantity`, `quantities`, `probability`, `probabilities`, `keep_counts` no longer have separate variants for each comparison; instead, they now take a comparison argument. `quantities` and `probabilities` now accept a comparison argument but no longer accept a list of outcomes.

* Rename `keep_counts` to `keep_counts_ge`. Add `le`, `lt`, `gt`, `eq`, and `ne` variants.
* Add `count_subset` evaluation that counts how many times the right side is contained in the left.
* Add `ImplicitConversionError` as subclass of `TypeError`.
* Add binary multiset operators to `Deck`.
* Add `modulo_counts` / `%` operation on multisets.
* Rebind generators and evaluate when fully bound non-generator expressions are given to an evaluator.
* Fix `Symbols` intersection.
* Fix argument order in `__rfloordiv__`.

* Fix `Symbols` operator priority with `Population`, `AgainExpression`.
* Added experimental `map_to_pool` and `explode_to_pool` methods.
* Split `compair` into `compare_lt` etc.
* Constructing a mixture of dice now effectively uses the old `lcm_joint` method, which reduces the denominator more aggressively.