We have a handful of dialogs that use $.modalBox to create a modal on the screen. In most cases, these have a "Close" or "Cancel" button, but pressing the escape key wouldn't do anything. This change adds some additional event handling to capture keypresses on the dialog itself as well as the overlay and the base body element. This is then plumbed into a "close" event triggered on the element, which the caller can handle to perform whatever action necessary to close the dialog. Testing Done: Used in conjuction with a change on the Review Board side.