Kwcoco

Changed
* Officially deprecate `kwcoco.util.util_delayed_poc`
* Remove the 2 suffix on the official `delayed_ops` node names.
* The delayed crop method can now simulated a padded slice.
* Changed ujson integration from opt-out to opt-in. Specify `KWCOCO_USE_UJSON` to use ujson.

Changed
* kwcoco will now use ujson to read json files by default if it is available.
* Added runtime deprecation noticed to deprecated functions
* Doctests now generate images for readthedocs.

Added
* Ability to "undo warps" from delayed ops.

Changed
* Removed Jagged from `delayed_ops`
* NaNs are now optimized like other leafs.

Fixed
* Bug where delayed nan did not have the right warp signature.
* Bug in boids when speed was 0.

Added
* `with_bundle` flag to `iter_image_filepaths`

Fixed
* Bug in sensorchan spec
* Issue in reroot and toydata generation that used incorrect bundle-dpaths
* Fixed issue in key parsing where numbers greater than 10 failed.

Changed
* Added `fpath` as an option to `CocoDataset.demo`, which is currently semi-stable.
* The `finalize` method for a DelayedOperation2 now calls prepare and optimize
beforehand by default, and also always returns an ndarray.
* DelayedWarp2 will now default to nan fill values when warping floats

Added
* Initial non-experimental version of SensorChanSpec with limited functionality
* Updated `kwcoco validate` cli tool with full options (and added checks for img attrs)
* New Delayed operations with a more scalable design

Fixed
* Fix compatibility issue with datasets that do not contain an annotations list
* Issue where the original coco polygons did not validate correctly in the schema.
* The new delayed operations now always return an arraylike

Changed
* FusedChannelSpec now has an `__eq__` method that returns True if the parsed reprs are the same.