A little improvement in blorkmarking.

When I come into a page through a blorkmark, the crumb trail is kind of pointless.

Here's a screen shot to illustrate.

The plan is simple. If there's a single element in the crumb trail, don't display anything there.

Let's see how it goes. It works pretty nicely.

If you come here through the hierarchy, however, you should get the crumb trail.

And if you come through the blorkmark, no trail