* Created Elasticsearch 2 backend
* Added tests for Elasticsearch 2 backend
* Split models up into different indices
pages, images and documents are now in separate indices
* Prefix fields of child models to prevent mapping clashes
* Replaced index_analyzer with analyzer/search_analyzer
index_analyzer has been removed in Elasticsearch 2.0
https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking_20_mapping_changes.html#_analyzer_mappings
There's no indication in Elasticsearch's docs that this wouldn't work on Elasticsearch 1.x. However, we found that the new configuration isn't reliable on Elasticsearch 1.6 and below (causes the test_query_analyzer test to fail randomly).
* Implemented new way of representing content types in search index
Instead of using a long string of model names that is queried using a
"prefix" query, we instead use a multi-value string field and query it
using a simple "match" query.
The only reason why this isn't implemented in the Elasticsearch 1.x
backend yet is backwards compatibility
* Added another child model of SearchTest with clashing field mapping
This checks that the namespacing of fields on child models is working properly (if it doesn't the update_index tests will fail)
* Added tests for get_model_root function
* fixup! Added tests for get_model_root function
* Docs updates for Elasticsearch 2 support
Also tweak examples to use elasticsearch2 backend by default
* Test against Elasticsearch 2 on travis
