The summary page can rely on the Config object to create
lists of relevant steps; this code was declared but not
defined / implemented for Config (but also not called, so
it was ok). This is basically shuffling bits around in
preparation for using the model directly, rather than
re-implementing the widget-creation code.
While here, split off the page-resizing into a free function
so that the code reads nicer.
Rather than Config asking its (owning) ViewStep what the title
is -- all existing implementations have a prettyName() for that --
move the title into Config and re-do-the ViewSteps to use it.
Rename init() to something meaningful.
- the Page displays a simple message describing what the
summary is all about; Config has the same message,
use that. Needed some re-jigging to get the signals
and slots right.
