A directive to delay the update of bound variable. E.g. update a variable after an animation completes.
Usage:
``
The contents of the div will be set to the result of evaluating `myBoundVar` in the current scope. When `myBoundVar` changes the contents of the div will change after a short delay.
You can also specify the length of the time delay:
``
The delay value is in milliseconds, and will also be evaluated in the current scope. If you don't specify the delay it defaults to 1000 milliseconds.