Modal dialog wrongly closed by escape key

Created by: tomhicks

This might be a browser issue to do with how keyboard events are emitted, but anyway...

To reproduce (in Chrome, not tried other browsers):

1. Go to the Bootstrap JavaScript page (http://getbootstrap.com/javascript/#modals) and the modal Live Demo.
2. Click the button to open the modal, and wait until it is shown
3. Press Ctrl-S and wait for the browser's Save dialog to be shown
4. Press and hold the Escape key (the Save dialog will close)
5. Release the escape key

Expected behavior: The dialog should not close

Actual behavior: The dialog closes.

This is not just when you hold the escape key down for a long time - it'll happen with a normal press. I presume the escape key listener is on keyup, causing this behavior?