Longfellow

Added EventListener#addMissingEventListener.

Fixed EventListener#removeEventListener.

The bounce command now works when used with GlobalCommand.

Extend the list of supported protocols.

Capitalize broken.

Visibility handler now uses an event listener instead of a simple array.

No longer request the same frame URL twice.

When a page is preloaded, always block sources contained within blank frames. For now, this will trigger a page reload once the page is no longer hidden.

No longer mark data: and javascript: frames as unblockable.

Use Page.info.id instead of TOKEN.PAGE.

Removed unnecessary messages.js file.