* master: (22 commits)
Add proper toString() method to UpdateTask (#21582)
Fix `InternalEngine#isThrottled` to not always return `false`. (#21592)
add `ignore_missing` option to SplitProcessor (#20982)
fix trace_match behavior for when there is only one grok pattern (#21413)
Remove dead code from GetResponse.java
Fixes date range query using epoch with timezone (#21542)
Do not cache term queries. (#21566)
Updated dynamic mapper section
Docs: Clarify date_histogram bucket sizes for DST time zones
Handle release of 5.0.1
Fix skip reason for stats API parameters test
Reduce skip version for stats API parameter tests
Strict level parsing for indices stats
Remove cluster update task when task times out (#21578)
[DOCS] Mention "all-fields" mode doesn't search across nested documents
InternalTestCluster: when restarting a node we should validate the cluster is formed via the node we just restarted
Fixed bad asciidoc in boolean mapping docs
Fixed bad asciidoc ID in node stats
Be strict when parsing values searching for booleans (#21555)
Fix time zone rounding edge case for DST overlaps
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