function createTabPanel(path, name, options, callback) {
    tabbar.addPanel(new wtf.app.AddonTabPanel(
        addon, documentView, path, name, options, callback));
  }
Creates a new tab panel.
Part of the app addon API.
@param {string} path Path used for navigation.
@param {string} name Panel name.
@param {Object} options Options.
@param {wtf.app.AddonTabPanel.Callback} callback
    A callback that creates an external panel.