visibility of IMDI fields in Arbil

It seems that IMDI newbies could get confused by the fact that not all available metadata fields are immediately visible when you
create a new session. Actors, for example, have to be added explicitly, so you kind of have to know they are there. I think this is a possible pitfall for new users that should be taken into account in the documentation (and maybe even in the user interface).

There are a number of ways to achieve this: I have at one point
experimented with incorporating a javascript like interpreter into
Arbil which would be very useful for advanced users, however this is
quite a bit of work to do. A simpler approach is add some hyperlink actions
(create corpus, session, actor etc.) into the help text so that simple html can be used as a wizard script
that guides the user through the process of creating a session with
actors etc.