Circleguard

* loading replays from cache is now roughly twice as fast

* don't fatal error when rng seed is not present when we expect it to be
* fix wrong name to int mappings
* add scorev2 (fixes fatal error on attempting to parse a replay with the scorev2 mod)

* add `cg.steal_check`, `cg.relax_check`, and `cg.correction_check` as convenience methods. These methods call `cg.run` internally
* don't require `Check` when using `cg.run`. `cg.run` now accepts an iterable of `Loadable`s and a `Detect`
* provide cvUR as `result.ur` and ucvUR as `result.ucv_ur`
* add new `Span` class, which can be used to represent a range of numbers with a string
* remove `num` argument to loadables. Use the `Span` class, or an appropriate string, instead
* remove `ischeat` from `Result`s and remove thresholds for determining a cheated replay. Users should determine their own threholds and check against `Result` attributes
* make `Detect` an `IntFlag` instead of a full class
* add default `load` and `load_info` implementations to `LoadableContainer`
* don't use `Replay.__init__` to process replay data. Use `Replay_process_replay_data` instead
* require `cache` in `Loadable` instantiation
* add `Loader.MAX_MAP_SPAN` and `Loader.MAX_USER_SPAN`, representing the most replays you can get from a map and user respectively

* fix error while investigating replays with no replay data

* fix error when loading a replay that has replay info but is not downloadable
* InfoLoadable renamed to LoadableContainer
* cache passed as part of super call
* `__eq__` required for Loadable
* `num_replays` method removed (should use `len(loadable_container.all_replays()` instead)
* all_replays required by `LoadableContainer`, not `Loadable`
* default implementation of `__iter__` and `__getitem__` in LoadableContainer
* `check.all_replays()` now returns the expected value (`loadables1 + loadables2`), new method `all_replays1` which returns only the replays in `loadables1`.

* parse rng seed value from last frame of lzma (previously, nonsensical values such as -12345|0|0|10186099 were stored in the replay data)