Update cat.nodes regex

Support for multi-word node names like 'Henry "Hank" McCoy'
Snapshot/Restore: fix snapshot of a single closed index

Snapshot of a closed index can leave snapshot hanging in initializing state.

Fixes #8046
Docs: add the predefined language-specific stopword lists to stop-tokenfilter.asciidoc
Docs: adds note about using null_value with dynamic templates

Closes #7874
Docs: Fix order for PUT _mapping docs

Closes #8083
Docs: Added RethinkDB River to list of community plugins

Closes #8016
Docs: Update query-string-query.asciidoc

Update sample

Closes #8024