Fix transient testScore failure by making DF consistent for query.
Share numeric data analyzer instances between mappings
use similar mechanism that shares numeric analyzers for long/double/... for dates as well. This has nice memory save properties with many date fields mapping case, as well as analysis saves (thread local resources)
closes #6843
Releasable XContentBuilder
make the builder releasable (auto closeable), and use it in shards state
also make XContentParser releasable (AutoCloseable) and not closeable since it doesn't throw an IOException
closes #6869
[AGGS] Pass current docid being processed to scripts.

Scripts may internally cache based on docid (as expressions do). This
change makes numeric aggregations using scripts pass the docid when
it changes.
Store: Only send shard exists requests if shards exist locally on disk and are not allocated on that node according to the cluster state.

Closes #6870
Threadpool Info: Allow to serialize negative thread pool sizes

As a SizeValue is used for serializing the thread pool size, a negative number
resulted in throwing an exception when deserializing (using -ea an assertionerror
was thrown).

This fixes a check for changing the serialization logic, so that negative numbers are read correctly, by adding an internal UNBOUNDED value.

Closes #6325
Closes #5357