Experimentally add a WIP list

I regularly filter the main agenda view for the CONT tag to see my WIP items, so
it's propably meaningful to have this as extra list.  It's using some space in
the agenda view, though, so let's see how this will turn out.

init.el

@@ -1078,7 +1078,7 @@
                              ((org-agenda-overriding-header "WIP List (TODO=\"CONT\", all items)")
                               (org-agenda-sorting-strategy '(priority-down category-up))))
                   (tags-todo "TODO<>\"CONT\"-HOLD-SOMEWHEN-DATE-WAIT/-DONE"
-                             ((org-agenda-overriding-header "Open Actions List (not WIP, not scheduled in the future)")
+                             ((org-agenda-overriding-header "Next Actions List (not WIP, not scheduled in the future)")
                               (org-tags-match-list-sublevels t)
                               (org-agenda-todo-ignore-scheduled 'future)
                               (org-agenda-sorting-strategy '(priority-down category-up))))))