Implement a simple forking option

[ehmatthes]

Implement a simple forking option when creating a new school, so new users can use one of the site's main strengths - not having to reinvent the wheel. Copy all elements, but no editor relationships.

• What are the critical tests to write?
• Where do the links to do this exist?
• What's the workflow for doing this?

[ehmatthes]

• Critical tests: (see Write more tests for views.fork #103)
  • Rejects a non-empty organization.
  • Check that only public organizations can be forked.
  • Fork an organization, and make sure all elements in the new organization match the old organization.
  • Check there's nothing in new org that's not in old org.
  • Make sure original org is unchanged, in all aspects.
  • Add a new sa to old organization, make sure it's in old organization and not in new organization.
  • Add new sa to new organization, make sure it's in new organization and not in old organization.
  • Make sure user forking is the only editor of the new organization.
• Further tests:
  • Make sure only public elements are in new org. (Actually, easy enough to do in checking that systems match.)

[ehmatthes]

• UI/ links
  • User creates a new organization.
  • On the organization page, after stating no elements, link to fork.
  • On forking page, can only fork public orgs now. (Later, could fork private orgs that you have edit access on.)
  • utils.fork() only copies public elements.
  • [ ] Will need to report errors in forking process to user. later (fork() reports errors to user #100)

[ehmatthes]

Rest of the tests moved to #103.