[DOCS] Added section describing how to return only agg results

Closes #5875
[TEST] Fix SimpleQueryTests.testRangeQuery assumptions.

This test assumed that the `num` field was mapped as an integer on all shards
and thus that all of them should fail when providing a timezone. However, since
it used dynamic mappings, some shards might have this field not mapped, as a
consequence they didn't fail.
Mapping: fixes dynamic mapping of geo_point fields

If a dynamic mapping for a geo_point field is defined and the first document specifies the value of the field as a geo_point array, the dynamic mapping throws an error as the array is broken into individual number before consulting the dynamic mapping configuration.  This change adds a check of the dynamic mapping before the array is split into individual numbers.

Closes #6939
[Build] @Nullable annotation is not applied to primitive types.
[Build] Make Eclipse aware of Elasticsearch's Nullable annotation for null pointer dereference analysis.
Internal: Fix a very rare case of corruption in compression used for
internal cluster communication.

See CorruptedCompressorTests for details on how this bug can be hit.
This change also removes the ability to use the unsafe variant of
ChunkedEncoder, removing support for the compress.lzf.decoder setting.
Core: Pass down the types from the delete mapping request to the delete by query request.

The `.percolator` type is a hidden type and therefor the types from the delete mapping request should passed down to the delete by query request, otherwise the percolator type gets ignored and the percolator queries don't get deleted from disk (only unregistered).

Closes #7087
Internal: adjusted visibility of GetRequest members (from protected to private) and resolved warning
[DOCS] fixed DeleteIndexedScriptResponse javadocs
Core: Avoid null references that may be returned due to concurrent changes or inconsistent cluster state

Closes #7181
Mappings: Make sure that multi fields are serialized in alphabetic order to ensure that the source is always the same.

Closes #7215
Test: don't need to wait for concrete mappings since we map both fields when we create the index
Internal: adjusted TermVectorRequest serialization to not serialize and de-serialize the index twice

Closes #7221
Geo: fixes geo_shapes which intersect dateline

If a geo_shape had edges which either ran vertically along the dateline or touched the date line but did not cross it they would fail to parse.  This is because the code which splits a polygon along the dateline did not take into account the case where the polygon touched but did not cross the dateline.  This PR fixes those issues and provides tests for them.

Close #7016
Geo: Better error for invalid multipolygon

Closes #7126
Add translog checksums

Switches TranslogStreams to check a header in the file to determine the
translog format, delegating to the version-specific stream.

Version 1 of the translog format writes a 0xffff_ffff_0000_0001 header
at the beginning of the file and appends a checksum for each translog
operation written.

Also refactors much of the translog operations, such as merging
.hasNext() and .next() in FsChannelSnapshot

Relates to #6554