bug 839214 - add celery tasks for es indexing

elasticutils tasks broken; add tasks in search app

test
bug 839214 - live indexing into elastic search

Code borrowed in large part from mozilla/fjord

update elasticutils, using pyelasticsearch with updated requests library

update test-utils library to eagerly test celery tasks
update tests for new test-utils
(some) code cleanup
remove obsolete search tests

don't ignore settings_test
new bulk reindex command

remove sphinx modules from search app
waffle search view to ES
disable ES_LIVE_INDEX during tests
Improve support for the user's language preferences.
Fix ValueError: too many values to unpack.
Fix NameError: global name 'ranked' is not defined.
Fix bug 850656: Set based_on field correctly
Fix bug 812728: Rev dash - Add filter for changes from new users
fix test mocks to match new requests version
Check if empty, use MIN(), explain query, correct id
Merge pull request #931 from Elchi3/new-docs-850656

Fix bug 850656: Set based_on field correctly
Merge pull request #932 from Elchi3/dash-newusers-812728

Fix bug 812728: Rev dash - Add filter for changes from new users
bug 812728 - waffle new user filter
Merge pull request #934 from groovecoder/waffle-dash-new-user-filter-812728

bug 812728 - waffle new user filter
Merge pull request #930 from GPHemsley/languages

Improve support for the user's language preferences.