When creating a Property, the default Collection should depend on the Type

(User Story, Closed -> Fixed, Priority: Critical, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Editor, UX
Summary: Currently, we default to ExactlyOne for everything. That's idiotic -- ExactlyOne is rarely the correct Collection. Instead, it should depend on the Type.
Note that the default should be Set for Tags, and Optional for almost everything else.
Implication: the Collection should be set after the Type in the UI, rather than before.