Plain URLs should render as links in preview
If write a markdown Question like:
http://google.com
^ plain link
The preview doesn't render this as a hyperlink -- but the question, once submitted, doe have a hyperlink here. A live preview of the link would be helpful. (This is what StackExchange does, for example.)
Testing: Internal askbot instance does not parse markdown properly in comment. I should be able to click this [link](http://www.google.com/)