[TEST] added missing wait for yellow in put warmer REST test
Added the `DistanceUnit.NAUTICALMILES` enumeration
label with the corresponding *NM* and *nmi* unit
suffixes. Update the docs to match.

Closes #5085
Update get.asciidoc

Minor improvements.

curl -XHEAD doesn't actually print anything so I've changed to use -I which actually prints the headers received.
[DOCS] improved get docs

- added _version to response
- exists call use -XHEAD with -i flag to include headers in the output
Make sure that parent type is created explicitly.
Cleaned up the p/c integration tests to use shorter mapping definition, ensureGreen() and .get()
Fixed issue where highlighting in percolate existing doc api doesn't work (no highlight snippets)
code coverage hookup
Add preserve original token option to ASCIIFolding

Closes #4931
Add support for `lowercase_expanded_terms` flag to simple_query_string

Default the flag to true, making simple_query_string behave similarly to
query_string

Fixes #5008
Fix license header for SimpleQueryParser
Enable percolation for nested documents

closes #5082