[DX] adding error messages to {ResultSet,ActionsRegistry}.possible_actions
Try to make it more accessible, when we first encountered these errors
it it didn't made any sense to us.
/* sortable tables */
table.listing tr .headerSortUp {
background-image: url(asc.gif);
}
table.listing tr .headerSortDown {
background-image: url(desc.gif);
}
table.listing tr .headerSortDown, table.listing tr .headerSortUp {
background-color: %(listingBorderColor)s;
background-repeat: no-repeat;
background-position: center right;
}