Migrate to Elasticsearch 1.x

This migrates Archivematica to Elasticsearch 1.x (tested with 1.3.4), and the official Elasticsearch Python library instead of pyes.

Known issues:

* [x] Number of files in an AIP does not display correctly in the advanced search view
```if 'isPartOf' not in aip:``` is more idiomatic.  Also, add comment explaining this is adding values for things that weren't in the fetched values? I was confused what this was doing initially.