<% Layout.switch %>
overwrite the switch macro in antvillelib for certain properties (but pass others thru)

Sourcecode in Layout/macros.js:
1:   function switch_macro(param) {
2:      if (param.name == "active") {
3:         var currLayout = res.handlers.context.getLayout();
4:         return currLayout == this ? param.on : param.off;
5:      }
6:      HopObject.prototype.apply(this, [param]);
7:      return;
8:   }