Added tests for match/multimatch queries with invalid “type” JSON param
Added dedicated test for MultiMatchQuery
[TEST] fixed typo s/mising/missing
[TEST] added missing put warmer body
[TEST] added ability to filter REST test sections to run

Added `tests.rest.section` parameter that allows to filter the test sections that get executed via regex (case insensitive)
Remove the in memory buffer Lucene store/directory
closes #4994
fix docs to reflect removal of byte buffer memory
Add [0.90.11] version as a constant
Improve Aggregations documentation

* Mostly minor things like typos and grammar stuff
* Some clarifications
* The note on the deprecation was ambiguous. I've removed the problematic part so that it now definitely says it's deprecated
Fix confusing sentence

The original sentence didn't make much sense. I hope this is a bit better. Taken heavy inspiration from https://github.com/elasticsearch/elasticsearch/commit/c63d8c4fb566882bd4655ddc7dec13b4e8719244