Register problem in 2.4.1 - release BLOCKED

[J. Alex Aycinena]

Christian, Phil,

I've re-applied the changes in r20359 with a one line change which I
believe caused the CRIT <gtk> warning:

   CRIT <Gtk> gtk_tree_sortable_set_sort_func: assertion
`sort_column_id >= 0' failed

The comments in gnc-tree-view.h, "Use GNC_TREE_VIEW_COLUMN_DATA_NONE
if you plan on using a non-model data source for this column" are
wrong and using it caused the problem later in the
"gnc_tree_view_add_text_column" routine when it tries to set up
sorting for the column. So I use GNC_TREE_MODEL_ACCOUNT_COL_TAX_INFO
and then afterwards link it instead to the data function.

It works properly and generates no warnings.

I don't believe these changes had anything to do with the
'gtk_widget_is_ancestor warnings' Phil saw, but of course I could be
wrong about that. Also I checked to see if it caused the other
register behaviour problems that Phil noted and I don't see them.

Phil could you confirm?

Thanks,

Alex