Load in self if window.opener happens to be gone.
Tools visibility update

Only show close button in iframe mode. Not needed anywhere else. Will
likely to switch to hidden by default,
and only show when necessary. (cc @MichaelArestad fyi: re: related css).

Only show URL scan bar when none was passed, in all modes. Might
eventually have a button to toggle visibility on demand, but no need to
clutter UI with it when a URL was already requested.
Improving source_data_fetch_fallback()

To add to existing data if passed rather than only add some if none was
passed.