This is mostly deprecation fixes and blueprint changes. There
are some dependency updates too; the changes to Ember
Basic Dropdown necessitated changing it to angle bracket
component invocation. The conversion of the rest of the
templates will happen separately.
Since DOM code is in a run.next, it's possible that between the DOM
code being queued and running the element is destroyed. So the DOM
code needs to guard against this using the isDestroyed API.