Actually Eclipse works like item 4.a: when you create the project form
existing source, it adds each sub-folder to the build path, but besides
that folder-like appearance I've noted, if you take a look on how this
configuration is done (project's properties) then you'll see a lot of
inclusion and exclusion filters that look weird.
I don't know if this is the behavior you're talking about. If true, then I
think that just the *directory of the script* could be added silently and
dynamically as a "working directory" when running the script. This way we
wouldn't need to create and update all that rules I mentioned above for
build path except if we want a special behavior.
It's like outside the IDE: you don't need to give -I"./" to ruby
interpreter because it's already aware about considering the script's
directory as a place to look up required stuff.
If my suggestion would be implemented, then when you run a script, Eclipse
would try to look up stuff from the same directory of the script
**regardless** of build path including that directory or not. Just like
you are setting working directory on Run dialog every time you run the
script, but now Eclipse would be doing it by itself, silently and
automatically.
I'm not that good in English but hope you can understand what I'm saying.