not printing activities at all when no progress information is available
hides *all* progress information from e.g. flake show. this is not ideal
and needs to be fixed, but the fix *still* has problems with flake show:
in multiline mode we will overwrite all useful flake show output as soon
as the progress bar is redrawn. flake show output is also mangled in any
number of other situations (like -v being set), so we should probably be
not too worried about it and fix progress reporting properly another day
Change-Id: I6d39d670e261bbae00560b6a8e15dec8e16b35c4