add url view+discussion

(great thought, Ethan)

added test, though it's somewhat meager, since the complete url will vary with testing environment.

  --Ethan McCutchen.....Sun Feb 20 13:07:29 -0800 2011

second example in http://test.dwagn.org/wagn/Menu_url but I think that's already ticketed.

  --John Abbe.....Sun Feb 20 15:37:38 -0800 2011

Yeah, same issue as make urls in content work within link syntax. It's about how link processing handles the inclusion, not about what the inclusion yields, so I'd rather track that concern in that ticket.

  --Ethan McCutchen.....Sun Feb 20 21:39:13 -0800 2011