When the schema definitions include acknowledgments for project collaboration, we should show these on property and enumerated value pages too, not just for per-term pages.

Note also that potentially multiple acknowledgements may be applicable to a single term. This is probably most true of types.

Background: we added per-property pages some time ago but didn't implement acknowledgements.

Also note that now that we have the notion of hosted extensions, the subdomain homepage for extension(s) e.g. http://bib.schema.org, http://auto.schema.org gives some additional place for explaining and linking to collaborative work.