/main_js_action
action to render external javascript

Sourcecode in Root/actions.js:
1:   function main_js_action() {
2:      res.dependsOn(res.handlers.layout.modifytime);
3:      res.dependsOn(res.handlers.layout.skins.getSkinSource("Root", "javascript"));
4:      res.digest();
5:      res.contentType = "text/javascript";
6:      root.renderSkin("javascript");
7:      root.renderSkin("systemscripts");
8:      return;
9:   }