Long render delay on web servers that block outbound port 80 traffic

The 2.2 release has code that refreshes the cached copy of widget.js from the twitter website on a regular basis. However, when hosted on a system where the firewall blocks outbound traffic to external websites, every request to enter a page featuring this block is delayed for 30 seconds while waiting for the http request process to fail.

I think an appropriate fix would be to include an option to turn off this widget.js cache refreshing feature, or to otherwise detect when the port is blocked so that the external request is not made.