Optimise clickable rows

Set a click handler on the table instead of on every row.  This should
be faster on large tables.  Also, it's easier to use: you just set the
clickable-rows class on the table, and the row-link class on the <a>
element that contains the "main" link of the row.

src/root/layout.tt

@@ -72,6 +72,13 @@
               });
           });
 
+          $("table.clickable-rows").click(function(event) {
+              if ($(event.target).closest("a").length) return;
+              link = $(event.target).parents("tr").find("a.row-link");
+              if (link.length == 1)
+                window.location = link.attr("href");
+          });
+
       });
 
     </script>