special status for state-log plain list elements?

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Is there any chance of building slightly on org-element's parsing of
plain-lists, so that it lists which represent state logs are somehow
noted as such? I'm imagining that `org-element-plain-list-parser' could
be augmented to provide a (:log t) property, or if we accept that
state-log lists are always unordered, the :type property could even just
be 'log.

For that it might be nice if list items knew if they were state-change
notes (State "WAIT" from "TODO", etc) or plain notes (Note taken on...
etc).

It's probably feature creep! But it would make some interesting things
easier. My most immediate use-case would be a function in the Agenda
which shows the most recent state log of the item under point. That way
you could see what an item was WAITing on, or what you're actually
supposed to do NEXT, and so on.

And, in the back of my head, I've always felt that Org should be able to
do arbitrary value logging -- sort of a generalization of org-clock.
That would be a project for a very rainy day indeed, but this would be a
bit of the groundwork done.

Anyway, let me know if this would be acceptable in principle (and to
what extent), and I can take a stab at a patch.

Eric