[lmi] Dataview vs. listview appearance

[Greg Chicares]

Changes to class census_view cause the appearance to change slightly,
even though the wxDataViewCtrl looks almost exactly like wxListView.
Can the old behavior be restored in the following two cases? Some end
user is certain to prefer the original behaviors even though the new
ones are arguably preferable--but I'd rather give them nothing to
argue about if we can do that without too much difficulty.

(1) Vertical spacing has widened. (It may be easier to read, but fewer
rows fit on the screen.)

(2) The default column width is now variable; it used to be fixed.
(Of course they can change that on the "Census" menu.)

I'll send a screenshot to Vaclav and Vadim in personal mail.