Unreified Old Tag Set names show up with dashes instead of spaces

Summary: When I have a Tag in an Old Tag Set (the only Tag Set Type prior to 0.4.6), and I click through to its pseudo-page, the Title shows up with dashes instead of spaces.

This one is, in principle, somewhat hard to fix. The problem is that New Tag Sets are based on Display Name instead of Name, and encode the URL differently, such that a dash is really a dash. So when the system gets a URL along the lines of "http://www.querki.net/me/mySpace/My-New-Thing", there is no clear way to distinguish whether this is an Old Tag Set value named "My New Thing", or a New Tag Set value named "My-New-Thing". (In the New Tag Sets, "My New Thing" would have the URL "http://www.querki.net/me/mySpace/My+New+Thing" -- using the more-standard "+" for spaces instead of our homebrew dashes.)

We may be able to fix this by changing the way we generate URLs for unknown names, but that's probably expensive and a bit risky -- it would involve taking an Old Tag (which is by definition a Name) and telling it to think of itself as a Display Name under this specific circumstance. And since the Old Tag Set will shortly be Deprecated, I'm going to tentatively call this bug low priority, and see how much we turn out to care in practice.