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
Monster commit Renames DocumentSeries to DocumentCollection.  Importer tests still red.