This way the text of the message can be configured from Rakefile.
Also, the default is now not to show the message - the message is
only added to page in "export" task.
Docs.live?'':'<div class="notice">Use <a href="http://docs.sencha.com/ext-js/4-0">http://docs.sencha.com/ext-js/4-0</a> for up to date documentation and features</div>',