Used ElasticsearchAssertions to check count result in RecoveryWhileUnderLoadTests
Fixed close index when the index is already closed

Closes #3601
Added log lines to log (debug level) acknowledgements regarding index alias creation and index state change
Added new iteration to RecoveryWhileUnderLoadTests

We want to check whether the issue causing the test to fail would be fixed by an additional refresh or not
Search action now log in debug what shards/nodes were used before moving to second phase
Added  a debug log for executing a refresh request on a shard.
Previously added logging in TransportRefreshAction caused NPE if search shards had errors (or was not yet started/assigned)
Better formatting for logging in TransportRefreshAction
Merge branch 'master' into master-sonar