Docs: Removed Sense mention
Update histogram-facet.asciidoc

Spotted a typo, which I've fixed.
[TEST] Fix ExistsMissingTests failures.

They were due to a combination of mappings propagation delays and the behavior
of MapperService.smartName(String) so mappings are now configured up-front.
start mapping service earlier to be available for recovery
Fixed JSON in fielddata docs
Core: The ignore_unavailable=true setting also ignores indices that are closed.

Closes #6471
Closes #6475
[TEST] Improve reproducibility of mappings propagation delays related issues.