/main_js_action
wrapper to make javascript.skin public

Sourcecode in Site/actions.js:
1:   function main_js_action() {
2:      res.dependsOn(this.modifytime);
3:      res.dependsOn(res.handlers.layout.modifytime);
4:      res.dependsOn(res.handlers.layout.skins.getSkinSource("Site", "javascript"));
5:      res.digest();
6:      res.contentType = "text/javascript";
7:      this.renderSkin("javascript");
8:      root.renderSkin("systemscripts");
9:      return;
10:  }