[tableview] enhance RelationColRenderer. Closes #2093184
* subvid should only be explicitly specified, or default when main view (vid)
is known to support it (eg 'list' / 'csv')
* new is_rtype_view boolean flag to ease usage of view based on original
entity with a relation name and role, as the 'reledit' view for instance
/* 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;
}