URI routing parameter does not work with Bulk API
closes #4053
URI routing parameter support with multi search API
Support URI level routing parameter for the multi search API, that will act as the default routing (unless explicitly set).
closes #4058
verify operations on store dir are executed when its open
call ensureOpen and properly set the open flag
also, better handling of failures and error message during listAll in local recovery
add keys/values to ImmutableOpenMap
More detailed logging  for FullRollingRestartTests.testFullRollingRestart

set indices.cluster  & cluster.service to TRACE
use immutable open map to list the files in store
Initial implementation of ResourceWatcherService

Closes #4062
[DOCS] Add some documentation about the performance of  `_source` usage in scripts.
[DOCS] Added a basic information about the official Ruby client to documentation
[DOC] Added a link to the official Ruby client to the "Clients" page
Added support for highlighting multi term queries using the postings highligter

Closes #4042