[js] lint : make it explicit that typeof is an operator, not a function.
Also, use === / !== except for null / undefined comparison
/* 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;
}