Fix JS part adder to work with no existing parts
Add summary field to Edition edit form.

Also removed default creation of blank part now that an edition can have no parts.
Mark title as a required field.
Resize govspeak help box to fill available space.
Remove redundant helper.
Merge pull request #9 from alphagov/additional_edition_fields

Additional edition fields
Merge remote branch 'origin/master' into alert-status

Conflicts:
	app/helpers/application_helper.rb
	app/views/admin/editions/edit.html.erb