Make DocumentSeries an edition

some methods commented out, will need to be revisited
Make admin document series controller be an edition controller

Also changed routes
Make admin templates work with DocumentSeries as edition

Added 'Series documents' tab as part of edition UI.
Add button to document menu to create DocumentSeries
Feature for creating document series and adding documents working.
Conflicts:

	app/helpers/admin/editions_helper.rb
	app/helpers/document_series_helper.rb
	app/models/document_series.rb
	app/models/document_series_group.rb
	app/presenters/publicationesque_presenter.rb
	app/views/admin/editions/_organisation_fields.html.erb
	app/views/layouts/admin.html.erb
	features/document-series.feature
	features/step_definitions/document_series_steps.rb
	test/support/model_helpers.rb
Satisfied original admin/document_series_controller_test.
Document series now displays correctly on front-end.
Document series' memberships are now cloned properly when re-drafted
Old route of document series now redirects to new
document series index properly
removed old logic about deleting document series
Removed document series index.
removed redundant helper
Rename document series to document collection

Including a database migration to rename the tables.
Use correct url helpers for document collections

Document collections should now use public_document_path which
calculates the url from the slug of the document.
More work to make tests pass doc series->collection rename
A few more test fixes
Tidy up document collection test
Remove warning about changes going live

They no longer go live immediately.
Fix up cucumber tests