Using AtomicArray to collect responses in mget and bulk indexing (instead of synchronised)
Add info to _cat/nodes, add _cat/indices.
AtomicArray.toArray will now throw an exception if target array if of the wrong size.
Added statistical facet to term facet in SimpleNestedTests

The test now uses a statistical facet plus a filter facet on nested documents.
rename variable and add comment about TopDocs#merge
Removed useless TODO
Fixed nullshape indexing.
Closes #3310
Added support for multiple indices in open/close index apis

Open/Close index api supports now multiple indices the same way as the delete index api works. The only exception is when dealing with all indices: it's required to explicitly use _all or a pattern that identifies all the indices, not just an empty array of indices. Supports the ignore_missing param too.
Added also a new flag action.disable_close_all_indices (default false) to disable closing all indices

Closes #3217
Added the "pattern_capture" token filter from Lucene 4.4

The XPatternCaptureGroupTokenFilter.java file can be removed once we
upgrade to Lucene 4.4.

This change required the addition of getArray() to Settings.java, as
getAsArray() could have broken patterns by trying to treat a single
string as a comma-delimited value.

Closes #3340