Copied the extension script tutorial files out of the Scripts
directory and into the Tutorial directory. This makes more sense,
and makes it possible to expand the script sample without altering
the tutorial.
Reverted the Scripts sample to be an actual sample, rather than a
tutorial.
Renumbered the last two tutorials and added them to the ToC. This
gives them actual numbers rather than treating them as add-ons to
the advanced tutorial.
Moved the source files for the tutorial binaries into a subdirectory
to reduce clutter.
This does mean we have two separate copies of the inline string
sample plugins, but that's an artifact of our attempts at security.
