First cut at an rs-dropdown directive.
Stub out a spec.
Work with link or button dropdown triggers.
Clean up jshint errors.
Detach and re-attach the menu element.

I had to override an inherited `min-width: 100%` property to get it to
size properly. but it's working.
Commit and push => notice console.log
Single-quotes make jshint happy.
Just use a document click.menu handler.

Clicking within the `rs-dropdown` element shows that menu and hides any other
dropdown elements.
Clean up our event handlers on detach.
Wrap the displaced menu with in a container.

The container `<div>` is given all of the CSS classes of the parent element it
was originally detached from, keeping the menu styled correctly for
`.rs-utility-dropdown` or `.rs-primary-dropdown` dropdowns.