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:

* [ ] Number of files in an AIP does not display correctly in the advanced search view
I decided to have the template use the same keys we use in our ES index, so the results don't need to be rewritten in the view.