Switch to Elastic Search for whitehall public search

Adding Tire for searching
Fix pagenation as the simple dsl isn't working
Also set default date
Topic and org filtering
remove unused method and test
Move code out of search module into helper for forms
Simplifyed the expire_on_next_scheduled_publication call
Filter by person and announcement type
View all announcements link to filter by person
Provide default filters for publication type
Use seperate indexes for publication and announcement
Add Policy to ES and change index action
use my branch of tire to get around @attributes overloading
	tire pollutes the @attribute instance variable, pull request pending in
	mater repo, but there is another issue with master that it requires
	multi_json 1.3 which is not supported by activesupport 3.1 so until we
	update to rails 3.2 we can't use it

Extend searchable to index additional fields used for filtering
Also removed old tests and prepare to move to rummager
rummerager integration and skip validate_structure

Use alphagov/tire
public_timestamp is used instead of timestamp_for_sorting
Fix announcement type filtering and start news article type