It's useful to have an example of an extension script that handles
multiple types of things. It's also good to show that scripts can
handle data types other than strings, and can chase an address to
format data items elsewhere in the code.
This required updating the tutorial binary, adding the new script,
and updating the tutorial text and associated screen shots.
Added a SourceGen tutorial with lots of screen shots. Uses
"responsive web design" so it works well on mobile devices.
This version is using jQuery load() calls to pull in pieces, but
that causes a lot of blink when loading because the loads are
asynchronous and may not complete until after the initial page
render has finished.
Tutorial prev/next links not yet working.
