Add ability to snapshot replicating primary shards

This change adds a new cluster state that waits for the replication of a shard to finish before starting snapshotting process. Because this change adds a new snapshot state, an pre-1.2.0 nodes will not be able to join the 1.2.0 cluster that is currently running snapshot/restore operation.

Closes #5531
[TEST] Disable dummy documents for QueryRescorerTests#testEquivalence
Benchmark abort accepts wildcard patterns

This adds support for sending a list of benchmark names and/or wildcard
patterns when submitting an abort request. Standard wildcards such as:
"*", "*xxx", and "xxx*" are supported. Multiple benchmark names and
wildcard patterns can be submitted together as a comma-separated list
from the REST API or as a string array from the Java API.

Closes #6185
Don't use AllTokenStream when no fields were boosted

AllTokenStream, used to index the _all field, adds some overhead, but
it's not necessary when no fields were boosted or when positions are
not indexed the _all field.

Closes #6187 Closes #6219
[TEST] Allow to disable plugin loading from classpath
[TEST] Wait for all benchmarks to be started if more than one is used
Verify that the current node is still master before the reroute is executed and if that isn't the case skip reroute
Invoke listener when reroute fails.

Closes #6244