remove irrelevant comment now that we pass the reuse strategy
Set queue sizes by default on bulk/index thread pools
Now that we properly fixed the ability to set the queue size on the index / bulk thread pool, we should actually set them to a somehow reasonable value to protect from users potentially overflowing our system.

I suggest defaults to be 50 for bulk, and 200 for indexing.

Also, set the thread pool for get, which we should set (in a similar value to a "read" queue size we have today).
closes #3888
Query String: Support multiple fields regexp queries
The query string query should apply regexp queries to execute on multiple fields as all the other queries.
closes #3901
test variations of multi field query string queries
[DOCS] Render common options on the same page
[DOCS] Reorganised common API conventions
Subclass ElasticSearchTestCase across the board

All tests in the test package should subclass ESTestCase to benefit from
random time-zones and locale etc.
s/ElasticSearch/Elasticsearch in src/test
Use smart client in busy waiting loop

This test fails since we use random transport clients. Let's see
if it stabelizes with a smart client in the loop and debug further
if it helps.