Update for core API changes

Core change Ib14c00df alters the output of action=paraminfo in ways that
need corresponding changes here for documentation to be properly fetched
and output.

This does the minimum necessary to keep ApiSandbox functioning; there
are further core changes both merged and upcoming that would allow more
enhancements to ApiSandbox (e.g. actually working for action=flow,
automatic token fetching, and so on), but actually doing so would take a
more comprehensive rewrite than I want to take on at this time.

Change-Id: I1028f56d7a92e0adcd4544f9624c270fa0e5e8af
Merge "Update for core API changes"