It would be nice to be able to select which columns in the Groups and
Headders panes are shown and hide the rest.  Eg, if desired have the Groups
view only show the 'Groups' and 'Unread' columns.

  It looks like it would be fairly easy to implement this for the Headders
pane and probably also for the Groups pane with a bit of modification; I've
managed a crude hack to do this on my system:

  For the Headder's pane I wanted to not display the Score and Lines
columns.  So, I set those two columns to be the last 2 to be displayed and
modified the ctree_new line (~2656) in pan/articlelist.c to display two
fewer columns:

Pan.article_ctree = w = gtk_ctree_new_with_titles
                            (articlelist_column_qty -2,  i, titles);

  As a quick and somewhat nasty hack, the Preferences dialog could have an
option for how namy columns to not display; a nicer implementation would
add a pseudo-item to the Column Layout selection of '- Not displayed -' or
similar to act as a cut between the desired and undesired columns.

  I used the same hack for the groups pane to lop off the last couple of
columns; unfortunately there is no option for what order the columns are
display in, so I was only able to remove the trailing fields that I didn't
want.  It would be desirable to be able to select what columns are shown
and in what order for this column view as well, but it would be a little
more involved to implement.