Richard Lake
Changed how storypanel.py keeps track of widgets from a list to a dict keyed on their title.
This is in order to speed up getConnectedWidgets which is used to paint widgets. The linear scan through a list was using a unreasonable amount of time in stories with large numbers of widgets.
 On a test story with ~800 passages this went from 13.7  to 0.137 milli-seconds per call.