Added new IndicesLifecycle.Listener method that allows to listen for any IndexShardState internal change.

Closes #4413
better cluster reroute allocation benchmark
Throw IAE if suggest results return differently sized results.

If the term suggester is used the results are merged depending on
the number of terms produced by the tokenizer / tokenfilter. If a
term suggester is executed across multiple indices that share the
same field but with different analysis chains we can't merge the
result anymore sicne tokens are our of order or have a different size.

This commit throws ESIllegalArgumentException if the number of entries
are not the same across all results.

Closes #3196
Make field data changes immediately taken into account and add the ability to disallow field data loading.

This commit changes field data configuration updates so that they are
immediately taken into account for loading new segments. The way it works
is that field data configuration is now cached separately from the field
data cache, meaning that it is now possible to clear the field data
configuration from IndexFieldDataService while the cache will stay around. On
the next time that Elasticsearch will reload field data configuration, it will
check if there is already a cache entry, and reuse it if it exists.

To disable field data loading, all that is required is to change the field
data format to "none" (supported by all field data types) using the update
mapping API. Elasticsearch will then refuse to load field data on any new
segment, but field data which has been loaded on the previous segments will
remain available. So you need to clear the field data cache in order to
reclaim memory (otherwise memory will be reclaimed slower, as segments get
merged).

Close #4430
Close #4431
Renamed top level `filter` to `post_filter`.

Closes #4119