[TEST] added support for replacing stashed values within objects and lists in our REST tests
[DOCS] Better document the limitation of nested objects.
Percentiles aggregation.

A new metric aggregation that can compute approximate values of arbitrary
percentiles.

Close #5323
Fix test bug: a too low compression level can make accuracy terrible.
[DOCS] Java API JSON typo
Terms aggs: only use ordinals on low-cardinality fields by default.

Close #5303
Fix sorting of NaN values in terms aggregations.

Closes #5236.
Added unit tests for terms and histogram sorting on sub aggregations that return NaN.
Fix NPE/AIOOBE when building a bucket which has not been collected.

Close #5048
Fix `metric` impl on unmapped fields.
Rewrite BytesStreamOutput on top of BigArrays/ByteArray.

Fix for #5159
check for null term in PagedBytesEstimator.bytesPerValue()

Fixes #5326
Implement custom circuit breaker estimator for parent/child field data