[up-dash] attribute without a value and also an [up-target] attribute.[up-expand] and if the
link also had an [up-dash] attribute.up.destroy() now returns a resolved deferred if the given selector or jQuery collection does not exist
If you're upgrading from an older Unpoly version you should load unpoly-migrate.js
to polyfill deprecated APIs.
Changes handled by unpoly-migrate.js are not considered breaking changes.
See our upgrading guide for details.