[TEST] Be more verbose if ClusterStatsTests fails
Make sure successful operations are correct if second phase is fast

In TransportSearchTypeAction we  need to increment successful ops
first before we increment and compare the exit condition otherwise if we
are fast we could concurrently update totalOps but then preempt one
of the threads which can cause the successor to read a wrong value from
successfulOps if second phase is very fast ie. searchType == count etc.
This can cause wrong success stats in the search response.
Rename successulOps to successfulOps in TransportSearchTypeAction
[TEST] return the correct transport instance in mock transport
Fixes typo in "Scan" search type documention
[BUILD] Remove site dependencies generation

Removed dependencies library generation.  It stalls Jenkins static analysis job
[TEST] use no replicas in MLT tests - doc mappers need to be present on all nodes
Text Query has been replaced by Match Query

Closes #5727.
[TEST] make BulkTest more robust if test infra is slow
[TEST] Add more randomization to bulk tests
Failed shards could be re-assigned to the same nodes if multiple replicas failed at once

After a shard fails on a node we assign a new replica on another node. This is important in order to avoid failing again due to node specific problems. In the rare case where two different replicas of the same shard failed in a short time span, we may fail to do so and assign one of them back to the node it's currently on. This happens if both shard failed events are processed within the same batch on the master.

Closes #5725
[TEST] Wait for LANGUID events to be processed before pulling stats
[TEST] Log where locks are created from if they are still open on close()
Revert "[TEST] Log where locks are created from if they are still open on close()"

This reverts commit 7eb8b0d0c0b2ef3adcfd7b1e10ea0ca9a50c1adc.
[TEST] Fix testRandomDirectoryIOExceptions to wait for green on reopen & add more assertions
Fix P/C assertions for rewrite reader

Inner queries must be rewritten as soon as a weight is pulled ie. must
be non-null.

Closes #5731
[Test] recoverWhileRelocating: Increase timeout while waiting for shards to replicate.
[TEST] RecoveryWhileunderLoadTests sometimes need higher timeouts

In some cases when we have a lot of docs with lots of shards
recovery takes longer than 1m causing the tests to fail before all
shards are recovered. This commit raises the timeout in this test to
5m max while it's rarely needed.

This commit also adds an assertion to ElasticsearchAssertions that
ensures that the cluster health requests are not hitting a timeout.
[TEST] MLT Rest test needs a mapping since we randomized number of nodes/shards
Remove plugin isolation feature for a future version

relates #5261