Enable all services to be deselected for a WWO

www.agileplannerapp.com/boards/173808/cards/8045
fixes: https://govuk.zendesk.com/agent/tickets/802017

adding a hidden field for the check box group for
services for a worldwide organisation, which enables
deselection of all services, similar to:

http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-check_box-label-Gotcha
Revert "Merge pull request #1869 from alphagov/content-ids-for-documents"

This reverts commit 9cad0acb37d846c3ba35608e4615c64250e723af, reversing
changes made to 6d98f262f053a6440eac45b937d2aaa62a7f3a0f.
Merge pull request #1868 from alphagov/fix-service-deselection

Enable all services to be deselected for a WWO