" but at some point I decided that the widget was no longer needed, so I commented out the widget's markup" SOURCE CONTROL, DO YOU SPEAK IT? In all seriousness, this is a major peeve of mine - the time that you're most confident that code can be deleted is when you're removing the pieces that depend on it. If the deletion really turns out to be wrong, you should be able to restore the code from source control. If you…
So you're saying you're an Ember.js user, huh?